chem 150 final
two samples of sodium chloride with different masses were decomposed into their constituent elements. One sample produced 1.36 g of sodium and 2.09 g of chlorine. being consistent with the law of constant composition, also called the law of definite proportions or law of definite composition, which set of masses could be the result of the decomposition of the other sample? a. 4.39 g of sodium and 6.76 g of chlorine b. 4.39 g of sodium and 1.27 g of chlorine c. 4.39 g of sodium and 9.66 g of chlorine d. 4.39 g of sodium and 3.51 g of chlorine
a . 4.39 g of sodium and 6.76 g of chlorine work: 2.09 / 1.36 = 1.54 6.76 / 4.39 = 1.54
pysical
a constant characteristic you observe with your senses
bond polarity
a measure of how equally or unequally the electrons in any covalent bond are shared - Bond polarity can be represented on a Lewis structure with either the partial symbol or with the arrow as shown below:
weight
a measure of the gravitational force acting on an object
the atomic theory
a theory that states that all matter is composed of tiny particles called atoms. - All atoms of a given element are alike and differ from the atoms of any other element - Compounds are formed when atoms of different elements combine in fixed proportions - A chemical reaction is a rearrangement of atoms- no atoms are created or destroyed
Use the atom builder interactive to arrange each atom or ion by mass number. (largest mass number to smallest mass number) a. four protons, three neutrons, and four electrons- mass #- 7 called Beryllium b. one proton, two neutrons, and two electrons - mass # 3 hydrogen c. two protons, four neutrons, and two electrons= helium 6 d. one proton, one neutron, and one electron= hydrogen 2 e. two protons, two neutrons, and two electrons = 4 helium
a, c, e, b, d
A depiction of a famous scientific experiment is given. Consider how the beam changes when the magnet is off compared to when the magnet is on. What type of beam was used in this experiment? a. cathode ray b. alpha particles c. proton beam d. neutron beam Who performed this experiment? a. Niels Bohr b. Ernest Rutherford c. J. J. Thomson d. Robert Millikan What did this experiment demonstrate? a. the charge‑to‑mass ratio of an electron b. that electrons are negatively charged c. that atoms have a positively charged nucleus d. the value of the charge of an electron
a. Cathode ray c. J.J. Thomson a. the charge-to-mass ratio of an electron
Which observation illustrates the law of conservation of mass? a. When 3 g of carbon reacts with 8 g of oxygen, 11 g of carbon dioxide is produced. b. The C:O mass ratio of one compound is exactly double that of another compound. c. The C:O mass ratio of a particular compound is the same, regardless of the size or source of the sample. d. Burning 10 g of propane produces twice as much carbon dioxide as burning 5 g of propane.
a. When 3 g of carbon reacts with 8 g of oxygen, 11 g of carbon dioxide is produced.
Group 1 on the periodic table
alkali metals - Li Na K Rb Cs Fr
Group 2 on the periodic table
alkaline earth metals - Be Mg Ca Sr Ba Ra
acid and bases definition Amphiprotic
amphiprotic: a molecule can behave as either an acid or a base Ex: HCO3 - , HSO4 - , H2O • Acids and bases can sometimes be described by more than one definition. Example: NH3 (aq) + H2O(l) → NH4 + + OH- ---- NH3 is an Arrhenius base because it increases [OH- ] in solution ---- NH3 is a Brønsted-Lowery base because it accepts a hydrogen ion • The terms "proton", "hydrogen ion" and "hydronium ion" are used interchangeably when describing acids in solution. --- Ex: the pH scale shows the relative number of hydrogen ions, H+ , in solution. But we know that without its one electron, the vast majority of hydrogen atoms would be a single proton. ------• 1H → 1H+ + e- - In solution, single protons join with water to make the hydronium ion, H3O+ , which is probably the most accurate of the three terms. • H+ + H2O → H3O+
alkali metals
any metal in Group 1A of the periodic table
Polyatomic Ions
are groups of covalently bonded atoms with a charge.
dipole-dipole forces
attractions between oppositely charged regions of polar molecules
Elements found to the left of the metalloids on the periodic table display which properties? a.They tend to form anions. b. They tend to form cations. c. They tend to be good conductors. d. They tend to be poor conductors. e. They tend to be lustrous. f. They tend to be dull in appearance.
b. They tend to form cations. c. They tend to be good conductors. e. They tend to be lustrous.
which of the following is not properly balanced and how would it be written correctly? a. p4 +6Cl2 -> 4PCl3 b. N2+O2 -> N2O c. Ca(OH)2 + 2 HBr -> CaBr2 + 2 H2O d. C3H8 +5O -> CO2 +4H2O
b. should be BALANCED EQUATION 2N2 + O2 -> 2N2O
Chapter 4 part 2
begins here
Write the formula for each compound. Carbon monoxide nitrogen trifluoride
carbon monoxide: CO nitrogen trifluoride: NF3
determine number of valence electrons in each of the neutral atoms carbon oxygen phosphorus nitrogen fluorine
carbon: 4 oxygen:6 phosphorus: 5 - 1s2 2s2 2p6 3s2 3p3--- 2 from the 3s and 3 from the 3p nitrogen: 5 fluorine: 7
designating matter
categories to choice from: Element, Compound, homog mix, hetorg mix 1. helium gas in a balloon- E or homog mix 2. orange juice- w/ pulp heterog mix 3. distilled water- compound 4. hydrogen peroxide, H2O2- Compound 5. Copper water pipe- homog mix 6. Air- homog mix 7. liquid oxygen- Element 8. gasoline- homog mix
properties
characteristics of matter
A + B ----> AB
combination
- CxHy + O2 ----> CO2 + H2O
combustion
element X forms three different compounds with element Y. Information about these compounds is contained in the table. compund 1: (formula XY6) (mass of Y per gram of X 2.82 g) compound 2: (formula XY ?) (mass of Y per gram of X 1.41 g) compound 3: (formula XY?) (mass of Yper gram of X 0.94 g) What are the formulas of compounds 2 and 3? Replace each question mark with the appropriate integer.
compound 2: XY3 compound 3: XY2
review compound formula, compound name, ans type of bond
compound formula: Mgl 2 compound name: magnesium iodide type of bond: ionic compound formula: MnCl2 compound name: magneses (II) chloride type of bond: ionic compound formula: P4O6 compound Name: Tetraphosphorus hexoxide type of bond: covalent compound formula: ZnCl2 compound name: Zinc (II) Chloride type of bond: ionic Compound Formula: SF2 Compound Name: sulfur difluoride type of bond: covalent
Identify the number of core and valence electrons for each atom for Ar, Ca, F
core electrons Ar- 10 Ca- 18 F-2 valence electrons Ar- 8 Ca- 2 F-7
atomic orbitals - d subshells
d subshells have 4 lobes or 2 lobes and a ring (dz2). There are 5 total d orbitals.
in 1911, Hans Geiger and Ernest Marsden, working under Ernest Rutherford, conducted an experiment involving alpha particles and gold foil that led to the discovery of the nucleus in atoms. The nucleus of an atom accounts for a. most of the size and mass of the atom. b. very little of the size and mass of the atom. c. most of the atom's size but very little of its mass. d. most of the atom's mass but very little of its size.
d. Most of the atom's mass, but very little of its size.
What is conserved when one balances a chemical equation? a. substances b. molecules c. reactants d. atoms e. products
d. atoms
AB ----> A + B
decomposition
pH scale definition
defintion: measurement system used to indicate the concentration of hydrogen ions (H+) in solution; ranges from 0 to 14 The pH scale is used to compare the relative strengths of acids and bases, since it is less cumbersome than reporting the [H+ ] or [OH- ] which can be very large or very small numbers. • pH= - log [H+ ] • pOH= -log [OH- ] • pH + pOH = 14
Functional Groups B. Compounds Containing a Single Bond to a Heteroatom
diethyl ether tetrahydrocannabinol
AB + CD ----> AD + CB
double displacement
acid and base
water can be both of these
Ni
what is the symbol for Nickel?
Cu
what is the symbol for copper?
Ag
what is the symbol for silver?
Iron
whats the chemical symbol Fe?
Germanium
whats the chemical symbol Ge?
Potassium
whats the chemical symbol K?
Krypton
whats the chemical symbol Kr?
9.60 where x is -2
write 0.0960 in scientific notation than find out what x is
2.917 where x is 2
write 291.7 in scientific notation than find out what x is: x 10^x
24 Cr 29Cu
{Ar }4s2 3d4 ^ 1 1 1 1 1 3d 1 4s
VSEPR
• "The best arrangement of a given number of electron domains is the one that minimizes the repulsions among them." • Electron pairs, whether they be bonding or nonbonding, repel each other • By assuming the electron pairs are placed as far as possible from each other, we can predict the shape of the molecule
molarity examples
• A chemistry lab procedure calls for 5.00 g of potassium hydroxide pellets to be dissolved in 500mL of water. What is the molarity of the resulting solution • When restocking the chemistry lab, the instructor purchased 4 L of a 1.75M sodium acetate buffer. How many grams of sodium acetate are in this container NOTEBOOK
Measuring Pressure
• A manometer is a device used to measure the difference in pressure between atmospheric pressure and that of a gas in a vessel
Pure Substances: Elements and Compounds
• A pure substance has distinct properties and a composition that does not vary from sample to sample. Atom: smallest part of an element that has all the properties of that element. Some elements are di, tri, or polyatomic in their simplest forms. Molecule: smallest part of a compound that has all the same properties of that compound. Molecules are made of atoms
Acid-Base Properties of Salt Solutions
• Anions are bases As such, they can react with water in a hydrolysis reaction to form OH- and the conjugate acid • Cations with acidic protons (like NH4 + ) will lower the pH of a solution • Most metal cations that are hydrated in solution also lower the pH of the solution • Attraction between nonbonding electrons on oxygen and the metal causes a shift of the electron density in water • This makes the O-H bond more polar and the water more acidic Greater charge and smaller size make a cation more acidic
Acids and Bases
• Arrhenius defined acids as substances that increase the concentration of H+ when dissolved in water. -- Brønsted and Lowry defined them as proton donors. -- Strong Acids: HCl, HI, HBr, HNO3 , H2 SO4 , HClO3 , HClO4 • Arrhenius defined bases as substances that increase the concentration of OH− when dissolved in water. --- Brønsted and Lowry defined them as proton acceptors. --- Strong Bases: LiOH, NaOH, KOH, RbOH, CsOH, Ca(OH)2 , Sr(OH)2 , Ba(OH)2
atoms vs Ions
• Atoms and ions are chemically different and have different properties - Examples Na and Na+ , Ca and Ca2+, Fe and Fe2+
Avogadro's Number and the Mole
• Because atoms are so small, it is impractical to work in the laboratory with relative masses of atoms. Chemists work with moles; a large enough number of atoms as to be convenient to measure and manipulate • Mole: an amount of matter that contains as many parts as the number of atoms in exactly 12g of isotopically pure carbon-12. - 1 mole = 6.02 x 10^23 parts
Lewis Symbols for Ionic Compounds
• In chemical reactions, atoms tend to gain, lose, or share electrons so as to have eight valence electrons. This is known as the octet rule • Metals lose electrons to take on the electron structure of the previous noble gas. In doing so, they form positive ions (cations) • Nonmetals tend to gain electrons to take on the electron structure of the next noble gas. In doing so, they form negative ions (anions) • Each group in the main group elements forms ions of a distinct charge.
VSERP
• In larger molecules, it makes more sense to talk about the geometry about a particular atom rather than the geometry of the molecule as a whole
Acid-Base Behavior and Chemical Structure
• In oxyacids, in which an -OH is bonded to another atom, Y, the more electronegative Y is, the more acidic the acid • For a series of oxyacids, acidity increases with the number of oxygens • Resonance in the conjugate bases of carboxylic acids stabilizes the base and makes the conjugate acid more acidic
Types of Electrons
• Inner (core) electrons (noble gas core) • Outer electrons (highest n) • Valence electrons (electrons involved in bonding) • Valence electrons are the electrons in the outermost principal energy level of an atom. • These are the electrons that are gained, lost, or shared in a chemical reaction. • Elements in a group or family have the same number of valence electrons.
Properties of Liquids-Viscosity
• Intermolecular forces have the most effect in the liquid and solid states • Resistance of a liquid to flow is called viscosity • It is related to the ease with which molecules can move past each other • Viscosity increases with stronger intermolecular forces and decreases with higher temperature
Solubility
• Ionic solids and strong acids dissociate into their component ions in water Strong acids: ---HCl, HI, HBr, HNO3 , H2 SO4 , HClO3 HClO4 • The anions of the ionic solid are solvated by the δ + charge on the water molecules and the cations by the δ - charge • This disrupts ionic bonding to completely dissolve ionic solids • Molecular compounds dissolve as intact molecules (no ions) due to their own δ + and δ - charges ----- Nonpolar molecular compounds (i.e.- unsubstituted alkanes) will not dissolve in water to any appreciable degree
Formulas and Names of Ionic Compounds
• Ions come together in small, whole number ratios that allow them to neutralize or cancel their opposite charges. • Sodium ions (Na+ ) and chloride ions (Cl- ) come together in a 1 to 1 ratio, indicated by the formula NaCl • Magnesium ions (Mg2+) and Oxygen ions (O2- ) come together in a 1 to 1 ratio, indicated by the formula MgO • The formula of an ionic compound made from Aluminum ions (Al3+) and Oxygen ions (O2- ) can be determined by "crossing over" the charge numbers (without the charge sign) as subscripts= Al2O3
Metals
• Luster • Solids (except Hg) • Malleable • Ductile • Conductors • Tend to form ionic compounds with non-metals • Tend to form cations in aqueous solution
Atoms
• Moseley accurately determined the atomic numbers of the elements, fixing the issues with the previous periodic tables (based on atomic weights) • Bombardment of atoms with high energy electrons causes them to emit X-rays of specific frequencies. When assigned whole numbers, these frequencies correspond with the number of protons in the nucleus.
Non-metals
• No luster, various colors • Usually brittle solids • Poor conductors • Tend to form anions or oxyanions in aqueous solution
Problems with the atomic theory
• Not all atoms of a given element are alike. Atoms can have different numbers of elections (ions) or neutrons (isotopes). Isotopes have different atomic masses. • Law of Conservation of Matter AND Energy allows creation of man-made elements • 18th and 19th century saw many discoveries and "discoveries" of different atom types (elements) • Dalton attempted to order the elements by assigning hydrogen an atomic mass of 1. Today's atomic masses are based on isotopically pure carbon-12 and are measured in atomic mass units (amu or u)
Electrolytic Solutions
• Pure water will not conduct electricity. Dissolved ions called electrolytes must be present for water to conduct electricity. • Strong electrolytes are substances that dissolve into ions in water (soluble ionic solids and strong acids) NaNO3 ---> Na+ + NO3 - • Weak electrolytes partially dissolve into ions in water (weak acids and bases) HClO2 <---> H+ + ClO2 - • Non-electrolytes do not dissolve into ions in water (molecular compounds other than the weak acids and bases) C6H12O6(s) --> C6H12O6(aq)
CH4 + 2O2 --> CO2 + 2H2O
• Reactants: to the left of the arrow • Products: to the right of the arrow • States: in italics and parentheses (s), (l), (g), (aq) • Coefficients: inserted in front of MOLECULES to balance the equation ------ NEVER change subscripts to balance equations
Brønsted-Lowry Acids and Bases
• Reactions between acids and bases always yield their conjugate bases and acids - Every acid has a conjugate base, ex. HX and X- - Every base has a conjugate acid, ex. H2O and H3O+
units of pressure
• SI Unit: Pascal (Pa, N/m2 ) often reported in kilopascals (kPa) • Non-SI Units: Atmospheres (atm), Millimeters of Mercury (mmHg), Torrs (torr) • 1 atm = 760 mmHg = 760 torr = 1.01325 ∙ 105 Pa =101.325kPa Example: Convert 745 torr to kPa 745 𝑡𝑜𝑟𝑟 (101.325 𝑘𝑃𝑎 / 760 𝑡𝑜𝑟𝑟) = 99.3 𝑘𝑃a
Molecular Shape and Molecular Polarity
• SO... A molecule of the type ABn is NONPOLAR if: - 1.) All the atoms around the central atom are the same type - 2.) The VSEPR shape of the molecule is one of the symmetric shapes: linear, trigonal planar, tetrahedral, square planar, trigonal bipyramidal and octahedral • Any other molecule with polar bonds is POLAR
Ideal Gas Law
• So far we've seen that - V 1/P (Boyle's law) - V T (Charles's law) - V n (Avogadro's law) • Combining these, we get - 𝑉 ∝ 𝑛𝑇 𝑃 • The constant of this proportionality is known as R, the gas constant PV=nRT
Characteristics of gases
• Unlike liquids and solids, gases - expand to fill their containers; homogenize easily - are highly compressible; molecules far apart - have extremely low densities and low molar masses - Liquids and solids can also exist as gases in their vapor state
Converting grams and moles
• Use the molar mass as a conversion factor • 1 mole of a substance = FW (in g) • Calculate the number of moles of potassium chloride in 4.50 g. • Calculate the mass of 0.53 moles of carbon tetrafluoride WORK IN NOTEBOOK
for each element identify the charge of its most common ion Na -3 -2 -1 +1 +2 +3
+1
for each element identify the charge of its most common ion Al +1 +2 +3 -1 -2 -3
+3
Law of Conservation of Mass
- Matter is not created nor destroyed in any chemical or physical change. - in any chemical reaction, the total mass of the reactants must equal the total mass of the products . - atoms are not created or destroyed in a chemical reaction. however, they may be rearranged, forming new substances
Avogadro's Number and the Mole • Calculate the formula mass of: - Sodium Azide, NaN3 - Ammonium Sulfate - Glucose, C6H12O6 - Calcium dihydrogen phosphate
- Sodium Azide, NaN3: 23.0 + 3(14.01) = 65.03 - Ammonium Sulfate: (look at polyatomic ion sheet) (NH4 +) (SO4 2-) (NH4)2 SO4 2(14.01) + 8 ( 1.01) + 32.1) + 4(16) = - Glucose, C6H12O6: - Calcium dihydrogen phosphate:
periodic table with ex
- We fill orbitals in increasing order of energy (Aufbau Principle). • Different blocks on the periodic table (shaded in different colors) correspond to different types of orbitals ex: electron configuration 17^Cl 1s^2 2s^2 2p^6 3s^2 3p^5
for each element identify the charge of its most common ion Cl: +2 -1 +1 +2 -3 +3
-1
for each element identify the charge of its most common ion Se -1 -3 -2 +1 +2 +3
-2
characterisitcs of matter
-All matter is made up of tiny particles called atoms -All atoms of a specific element are identical to each other and different from atoms of any other element -All compounds are combinations of the atoms of two or more elements - Every molecule of a specific compound always contains the same number of atoms of each kind of element found in the compound - In chemical reactions, atoms are rearranged, separated, or combined, but are never created or destroyed
ion-dipole interactions
-Ion-dipole interactions are important in solutions of ions. -The strength of these forces is what makes it possible for ionic substances to dissolve in polar solvents.
select the atoms or ions drawn with valid lewis dot structures
. . C . . and . . . O . . . N-has 5 val electrons O- has 6 val electrons C- has 4 val electrons
If the pH = 2 for an HNO3 solution, what is the concentration of HNO3 ? • 0.10 • 0.20 • 0.010 • 0.020 • 0.0010
0.010
Which chemical reactions are not possible according to Dalton's atomic theory? 1. CCl ^4⟶CH^4 2. N^2+3H^2⟶2NH^3 3. 2H^2+O^2⟶2H^2O+Au
1. CCl4⟶CH4 3. 2H2+O2⟶2H2O+Au
Carbonyl Containing Compounds
1. Compounds that have only C and H atoms bonded to the carbonyl group: •An aldehyde has at least one H atom bonded to the carbonyl group. •A ketone has two alkyl groups bonded to the carbonyl group. 2. Compounds that contain an electronegative atom (N or O) bonded to the carbonyl group:
Why study Chemisty?
Central Science -Study of matter Critical way to evaluate the world- Measurement/data collection, Data analysis, Scientific observations Systematic approach to problem solving- Scientific method
Group 6 on the periodic table
Chalcogens - O S Se Te Po
Chemical Sentences: Equations
Chemical equations represent the sentences in the language of chemistry. They communicate a chemical change using symbols and formulas to represent the elements and compounds involved in a chemical reaction.
Chemical Sentences: Equations coefficients
Coefficients are numbers used to balance a chemical equation. Never change the subscripts.
types of chemical reactions Combination
Combination: two or more reactants combine to form a larger product ---- When a combination reaction occurs between a metal element and a non-metal element, the product is an ionic solid. We can predict products, write, and balance equations for this type of combination reaction ----- Ex.: Aluminum and bromine react in a combination reaction aluminium bromide- Al 3+ br 1- Al (s) + Br2 --> AlBr3 not balanced to balance Al + 3 Br2--> 2AlBr3 (combination reactions)
Types of Chemical Reactions combustion
Combustion: Rapid reactions that produce a flame. For our purposes, most combustion reactions involve the reaction of hydrocarbons with oxygen in the air to produce carbon dioxide and water. Example: in middle school, we used alcohol burners to produce a flame for science experiments. The burners were filled with 2-propanol, C3H9O. Write and balance the equation for the combustion of 2-propanol C3H9O (l) + O2(g) ---> CO2 + H2) C 3 C 1 x3 H 9 H 2 O 1 +2 O 2+1
classify the statements as consistent or inconsistent with modern-day atomic theory: - all atoms of a given type are identical - atoms change identity during chemical change processes - different types of atoms exist - only whole atoms can participate in chemical reactions - atoms are the basic building blocks for all kinds of matter
Consistent: - different types of atoms exist - atoms are the basic building blocks for all kinds of matter - only whole atoms can participate in chemical reactions non -consistent: - all atoms of a given type are identical - atoms change identity during chemical change processes
1.19×10^−3 m= 1 190 000 nanometers
Convert 1.19×10^-3 to the equivalent length in nanometers.
5230000
Convert 5.23 x 10 -3 m to the equivalent length in nanometers.
determine number of protons, neutrons, and electrons present in each of the atoms Cr 53 Ru 103 S 34 Zn 67
Cr 53: protons: 24 neutrons: 29 electrons: 24 Ru 103: pro: 44 neu:59 ele: 44 S 34: pro: 16 neu: 18 ele: 16 Zn67: pro: 30 neu: 37 ele:30
Identify these elements based on their locations in the periodic table. Give the symbol, not the name. period 4, group 11 (1B)
Cu (Copper)
Cycloalkanes A. Simple Cycloalkanes
Cycloalkanes contain carbon atoms arranged in a ring.
density formula
D=mass/volume when added to water/liquid.....To find the density of any object, you need to know the Mass (grams) of the object, and its Volume (measured in mL or cm³). Divide the mass by the volume in order to get an object's Density.
Law of Multiple Proportions
Dalton • Elements can combine in more than one set of proportions, but each set will belong to a different compound with different properties. • Two compounds, ethylene and acetylene, both contain only carbon and hydrogen. A sample of acetylene contains 92.26 g of C and 7.74 g H. An ethylene sample contains 46.13 g C and 7.74 g H. If the formula for acetylene is C2H2 (two carbons : two hydrogens), the formula for ethylene is...
Types of Chemical Reactions decomposition
Decomposition: one substance undergoes a reaction to produce two or more other substances --- Products of decomposition reactions are not as easily predictable, but several examples exist of decomposition reactions where a larger reactant decomposes into elements --- Example: Sodium Azide (NaN3 ) decomposes rapidly in air into its component elements reaction: NaN3 (s) ---> Na + N2 (g) 2NaN3---> 2Na + 3Na
Law
Describes what happens. Does not explain how it happens
Chemical vs. Physical; properties and changes
Designate the following properties as chemical or physical properties Color -phy Size -phy Ductility- phy Flammability - chem Density- phy Compressibility- phy Designate the following changes as chemical or physical changes Burning match -chem Melting ice- phy Milk sours -chem Crushing limestone- phy Water evaporates- phy salt dissolves in water- phy Antacids (Alka Seltzer) dissolve in water- chem
Hypothesis
Educated guess. Untested explanation
Electron arrangement: the Quantum Model
Electron configurations allow us to show the distribution of all electrons in an atom. • Each component consists of: • A number denoting the energy level, • A letter denoting the type of orbital, • A superscript denoting the number of electrons in those orbitals ex: 1 s ^ 2 1: electrons are in the first shell s: electrons are in an s subshell 2: two electrons are in the 1s subshell
electronegativity def
Electronegativity is a measure of an atom's attraction for the electrons in a bond. Electrons in a bond can be shared: --- • Shared Equally (non-polar covalent bonds): Atoms have a difference in electronegativity <0.5 --- • Shared Unequally (polar covalent bonds): Atoms have a difference in electronegativity from 0.5-2.1 ----• Not Shared: (ionic bond) Parent atoms have a difference in electronegativity >2.1 ex: Na ----> Cl 0.9 3.0 = 2.1 = ionic bond (not shared) ex: C - Cl 2.5 3.0 = 0.5 ionic bond (shared unequally)
Metals
Elements that are good conductors of electric current and heat.
Nonmetals
Elements that are poor conductors of heat and electric current
Metalloids
Elements that have properties of both metals and nonmetals.
elements hydrogen
Hydrogen • Does not truly belong with any family. Has been classified at different times as a alkali metal, a noble gas, in the carbon family, and in the halogen family • Most abundant element in the universe and is the 3rd most abundant element on earth (mostly in compounds) • Has 3 isotopes • 1H: protium, 99.985% • 2H: deuterium, 0.015%, used for NMR solvents • 3H: tritium, radioactive, t1/2=12.35 years, only trace amounts naturally found on earth, produced in a nuclear reactor for tracer studies
nano- 10^{-9} centi- 10^{-2} milli-10^{-3} kilo-10^3 micro- 10^{-6} mega- 10^6
Identify the power of ten that defines each of these prefixes. Input your answers as 10𝑥10x where 𝑥x is the power of ten. ex: pico-10^-12 nano- centi- milli- kilo- micro- mega-
Theory
If a hypothesis has been repeated tested and has not been disproved, it may become accepted as a .....
Shapes and Properties: Polar and Nonpolar Molecules
In order for a molecule to be polar, two conditions must be met: 1. It must have polar bonds. 2. The bonds must be arranged such that a separation of charge exists
classify each compound as ionic or molecular CO2 CH4 ZnCl2 NaBr
Ionic ZnCl2 NaBr molecular: CO2 CH4
Dimitri Mendeleev
Organized elements by properties first and atomic weights second • Lothar Meyer proposed a similar table at the same time (1869)
Determine the chemical symbol for the neutral element corresponding to the electronic configuration. Use proper formatting; letter case matters: 1s²2s²2p⁶3s²3p⁶
P (phosphorous)
Pressure and its formula
P= (F/A) • Pressure is the amount of force applied to an area • Atmospheric pressure is the weight of air per unit of area • Gases exert pressure on all surfaces they touch
Consider the reaction of phosphine, PH3 with oxygen to form tetraphosphorus decoxide and water • When this equation is properly balanced how many molecules of water are produced for every molecule of tetraphosphorus decoxide formed?
PH3 + O 2 -> P4O10 + H20 BALANCED EQUATION: 4PH3+ 8O2 -> P4O10 + 6H2O - 6 bottles full of water for every 1 molecule of tetraphosphorus decoxide
orbital electron configuration
Pauli exclusion principle - no two electrons in an orbital can have the same spin (ms ). • Hund's rule: The most stable arrangement of electrons in subshells is the one with the greatest number of parallel spins.
limiting reactants
Pizza Analogy: Each pepperoni pizza requires 48 pepperoni. I have 129 pepperoni and 15 cheese pizzas. How many pepperoni pizzas can I make? - Theoretical yield: 2 pizza - Actual yield: - Percent yield:
atomic number 19 what is chemical symbol?
Potassium- K
quantum mechanics
Quantum: A tiny unit of energy produced or absorbed when an electron makes a transition from one energy level to another. - When electrons are in the lowest energy state,they are said to be in the ground state. - When energy from a flame or other source is absorbed by the electrons, they are promoted to a higher energy state (excited state) - When an electron in an excited state returns to a lower energy state, it emits a photon of energy, which may be observed as light. While we cannot determine the exact position of the electron we can define a region where we are likely to find it.
carboxylic acid
R-COOH
Ester
RCOOR
Ketone
RCOR
main group in periodic table called
Representative elements (1A-2A, 3A-8A)
Alkane Nomenclature B. Naming an Acyclic Alkane
STEP 1: Find the parent carbon chain and add the suffix. - •Find the longest continuous carbon chain, and name it with an "-ane " ending. •Find the longest continuous carbon chain, and name it with an "-ane " ending. •It does not matter if the chain is straight or has bends. •All three examples below have 6 C' s in their longest chain: example in PowerPoint STEP 2: Number the atoms in the carbon chain to give the first substituent the lower number STEP 3: Name and number the substituents. •Name the substituents as alkyl groups. •Use the numbers from step [2] to designate their location. •Every carbon belongs to either the longest chain or a substituent, but not both. •Each substituent needs its own number. •If two or more substituents are identical, use prefixes to indicate how many. •The following compound contains two methyl groups, so we use the name dimethyl for them. STEP 4: Combine substituent names and numbers + parent + suffix. •Alphabetize the substituents, ignoring prefixes. •Precede the name of each substituent by the number that indicates its location. •There must be one number for each substituent. •Separate numbers by commas and separate numbers from letters by dashes.
Schroedinger equation
Schroedinger solved this (with complicated calculus) and defined a wave function (psi, ). indiana univ symbol - • This function allows us to calculate the probability of finding the electron in space (2 ). Triggered a new field - quantum mechanics
Scientific Method
Scientific method: A flexible process of creative thinking and testing aimed at objective verifiable discoveries about how nature works • Differences between hypothesis, theories, and laws - Accurate and precise quantitative measurements
Identify the missing information for each neutral isotope. A Se atom has a mass number of 79. Determine the number of neutrons, protons, and electrons in this neutral isotope. A neutral isotope has a mass number of 65 and 36 neutrons. Identify the element symbol of this isotope and determine the number of protons and electrons.
Se: number of neutrons: 45 number of protons: 34 number of electrons: 34
noble gas core notation ex from Kr 36 to 54Xe
Shows in brackets the noble gas element that most nearly precedes the element being considered ex: { 36 Kr} 5s2 4d10 5p6
Identify these elements based on their locations in the periodic table. Give the symbol, not the name. period 3, group 14 (4A)
Si (Silicon)
Fussion
Smaller nuclei fusing together to form a large nucleus • Fusion would be a superior method of generating power. • The good news is that the products of the reaction are not radioactive. • The bad news is that in order to achieve fusion, the material must be in the plasma state at several million Kelvin.
stable electron configurations
Sodium can lose a valence electron. After doing so, its core electrons are configured like the noble gas neon • Once a sodium atom loses an electron, it becomes an ion. -Chlorine can gain an electron, and in doing so, its electron structure becomes like argon • The most stable ion of main group elements is isoelectronic with a noble gas. When atoms lose electrons the resulting ion has a positive charge, eg Na+ • When atoms gain electrons the resulting ion has a negative charge, eg Cl- • Which of the following are isoelectronic? ----- K + and Ar ----- Mg2+ and Ar ----- Ne and Cl- - Xe and Kr
Describing Matter- On a macroscopic level, matter can be described as a solid, liquid, or gas
Solid: Definite volume and shape Liquid: Definite volume, takes the shape of its container Gas: No definite volume or shape
Write the name for the compound. Spelling counts. SF4
Sulfur tetrafluoride
quantum mechanical model of the atom
The Bohr model still treats electrons primarily as particles. • Shifting to treating them like waves improved the model. • Standing waves: •---- like those in musical instruments - Each orbital can be fit to only certain standing waves (whole # of waves) • Each standing wave that "fits" an orbital has a different energy -------- (E = hn)
Molecular Shapes: The VSEPR Theory (only works for single centered atoms)
The Valence Shell Electron Pair Repulsion (VSEPR) - theory predicts the shape of molecules and polyatomic ions based on repulsions of electron pairs on central atoms.
Drawing Organic Molecules B. Skeletal Structures
When drawing a skeletal structure: •Assume there is a carbon atom at the junction of any two lines or at the end of any line •Assume there are enough hydrogens around each carbon to give it four bonds •Draw in all heteroatoms and the hydrogens directly bonded to them
Volume Relationships in Chemical Equations Avogadro's hypothesis:
When measured at the same temperature and pressure, volumes of all gases contain the same number of molecules. Avogadro's number is defined as the number of atoms in a 12-g sample of carbon-12 and is 6.02 x 1023 . 3H2 + N2 -> 2NH3
Naming Compounds with Polyatomic Ions
When naming compounds with polyatomic ions, simply name the ions in order. Example: (NH4 )2 SO4 ammonium sulfate
polar covalent bond
When two atoms with differing electronegativities form a bond, the bonding electrons are drawn closer to the atom with the higher electronegativity. Such a bond exhibits a separation of charge and is called a polar covalent bond
Writing Formulas Using Polyatomic Ions
When writing formulas for compounds containing polyatomic ions, it may be necessary to use parentheses to denote the proper number of the ions. Example: calcium nitrate Ca2+ NO3 - Ca(NO3 )2
a. a cheese sandwich is toasted b. milk turns sour in the refrigerator c. the nail heads in your deck rust
Which of the following are chemical changes? Check all that apply. a. a cheese sandwich is toasted b. milk turns sour in the refrigerator c. the nail heads in your deck rust d. baking soda, flour, salt, and water are mixed to make bread dough e. rock candy crystals precipitate from a concentrated sugar solution
C. The Copper roof turns green over time D. Baking soda is dissolved in vinegar and bubbles appear
Which of the following are chemical changes? Check all that apply. A. sugar is dissolved in water B. A warm coke bottle fizzes when opened C. The Copper roof turns green over time D. Baking soda is dissolved in vinegar and bubbles appear E. A fog appears on your windshield in cold weather
a. The ratio of a substance's mass to its volume, measured in grams per milliliter and also equivalent to grams per cubic centimeter.
Which of the statements best describes density? a. The ratio of a substance's mass to its volume, measured in grams per milliliter and also equivalent to grams per cubic centimeter. b. The mass that a mole of substance has, measured in grams per mole. c. The amount of substance dissolved in a liquid, measured in moles per liter. d. The mass of substance dissolved in a liquid, measured in grams per milliliter.
Sugar burns in air to form water and carbon dioxide.
Which of the statements describes a chemical property? Mercury is a liquid at room temperature. Titanium is less dense than iron. Sugar burns in air to form water and carbon dioxide. Water boils at 100 ∘C.
aquesous solution
• Water is often called the "universal solvent" because so many different compounds are able to dissolve to some degree in it. • Because oxygen is a much more electronegative element than hydrogen, electrons in the bonds of water are held closer to it, resulting in a partial negative charge on the oxygen (δ - ) and a partial positive charge on the hydrogens (δ + ). ----- Molecular compounds (like water) that have partial charges are known as polar compounds • During the solvation process, the partial charges on the water molecules separate the solute molecules by interacting with their opposite charges
Heisenberg uncertainty principle
• Waves extend into space so we can't know the exact position of a wave. • Heisenberg uncertainty principle: It is impossible to know simultaneously both the momentum (mass times velocity) and the position of the particle with certainty. ------• (∆𝑥)(∆𝑝) ≥ ℎ 4 / 4pie
Molarity and Stoichiometry examples
• What volume of 1.250 M HCl (aq) is required to react with 11.78 g Na2CO3 ? - Na2CO3 (s) + 2 HCl (aq) 2 NaCl (aq) + H2O (l) + CO2 (g) NOTEBOOK
Gas Producing Acid Base Reactions- accepts to the rule
• When a carbonate or bicarbonate reacts with an acid, the products are a salt, carbon dioxide, and water. - CaCO3 (s) + HCl (aq) ⎯→CaCl2 (aq) + CO2 (g) + H2O (l) • Similarly, when a sulfite reacts with an acid, the products are a salt, sulfur dioxide, and water. - SrSO3 (s) + 2 HI (aq) ⎯→SrI2 (aq) + SO2 (g) + H2O (l) • When a metal sulfide reacts with an acid, the products are a salt and hydrogen sulfide - Na2 S (aq) + H2 SO4 (aq) ⎯→ Na2 SO4 (aq) + H2 S (g)
VSEPR Linear
• When there are only 2 bonding domains, the only geometry available is linear - VSEPR geometries only apply to molecules of 3 or more atoms. Diatomic molecules are always linear
molar mass
• While a mole is always the same number of parts, the mass of a mole is a property of the substance being measured. • The molar mass (g/mole) of one mole of a substance is equal to its formula weight (in amu) ---- The mass of a single atom of an element (in amu) is numerically equal to the mass in grams of one mole of that element. ---- The formula or molecular weight of a substance (in amu) is equal to the mass of one mole of that compound (in grams)
Stoichiometric Conversions
• While the beauty of the dimensional analysis method is that any conversion can be accomplished, as long as you have conversion factors for it, stoichiometric conversions tend to be of three basic types. • Moles A ↔ Moles B: uses a mol ratio conversion (from the balanced chemical equation) • Moles A ↔ Mass B uses a mol ratio and a molar mass (from or calculated from the periodic table) • Mass A ↔ Mass B: uses a molar mass, a mol ratio, and another molar mass
atomic orbitals - f subshells
• f subshells have difficult shapes to describe and are only important for atoms with an atomic number greater than 57 so we won't worry about them.
atomic orbitals - P subshells
• p subshells have 2 lobes. There are 3 for each value of n, one in each direction (x,y,z) look like barbells with two lobes with three lines
functional groups
•A functional group is an atom or group of atoms with characteristic chemical and physical properties. •A functional group contains a heteroatom, a multiple bond, or sometimes both. •The letter R is used to abbreviate the carbon and hydrogen portion of a molecule.
Simple Alkanes C. Classifying Carbon Atoms
•A primary carbon (1 o C) is bonded to one other C. •A secondary carbon (2 o C) is bonded to two other C. •A tertiary carbon (3 o C) is bonded to three other C. •A quarternary carbon (4 o C) is bonded to four other C
Simple Alkanes B. Acyclic Alkanes Having Five or More Carbons
•After pentane, the following names apply: # of C' s , Name, Structure 6: hexane CH3CH2CH2CH2CH2CH3 7: heptane CH3CH2CH2CH2CH2CH2CH3 8: octane CH3CH2CH2CH2CH2CH2CH2CH3 9: nonane CH3CH2CH2CH2CH2CH2CH2CH2CH3 10: decane CH3CH2CH2CH2CH2CH2CH2CH2CH2CH3
Focus on Health & Medicine B. Health Effects of Alcohol Consumption
•Alcohol consumption in small amounts causes dizziness, giddiness, and decrease of social inhibitions. •Large amounts of alcohol causes decreased coordination and reaction time. •Even larger amounts result in coma or death. •Chronic excessive alcohol consumption leads to cirrhosis of the liver. •Pregnant women should not drink alcohol as the ethanol crosses the placenta and affects the fetus, which lacks the enzymes to metabolize it properly.
Alkyl Halides Interesting Alkyl Halides
•Chloromethane (CH3Cl) is produced by kelp, algae, and emissions from volcanoes. •Dichloromethane (CH2Cl2 ) is a solvent once used to decaffeinate coffee. •Trichloromethane (CHCl3 , chloroform) and tetrachloromethane (CCl4 , carbon tetrachloride) are useful industrially produced solvents that are toxic if inhaled or ingested.
Cycloalkanes
•Cycloalkanes contain C atoms joined in one or more rings. •They have the general formula CnH2n . All alkane molecules have names that end in the suffix "-ane."
Focus on Health & Medicine Ethers as Anesthetics
•Diethyl ether was first demonstrated as an anesthetic in 1846 by the dentist Dr. William Morton. •Prior to this, patients undergoing surgery had to tolerate excruciating pain. •Modern variations include the three ethers below:
Structure and Properties of Ethers A. Physical Properties
•Ether has two polar C—O bonds with a bent shape, therefore it has a net dipole. •Ether does not contain an H atom bonded to an O atom, so ether cannot form intermolecular hydrogen bonds.
Structure and Properties of Ethers
•Ethers have two alkyl groups bonded to an O atom. •The two alkyl groups can be the same, or they can be different. •An ether has an O atom with a bent shape like H2O, with a bond angle of 109.5o.
Cis-Trans Isomers B. Saturated and Unsaturated Fatty Acids
•Fatty acids are carboxylic acids (RCOOH) with long carbon chains of 12-20 carbon atoms. •Naturally occurring animal fats and vegetable oils are formed from fatty acids. •Saturated fatty acids have no double bonds in their long hydrocarbon chains. alkanes •Unsaturated fatty acids have one or more double bonds in their long hydrocarbon chains. alkunes •Generally, double bonds in naturally occurring fatty acids are cis. •As the number of double bonds in the fatty acid increases, the melting point decreases. •Fats are generally formed from fatty acids having few double bonds; they are solids at room temp. •Oils are generally formed from fatty acids having a larger number of double bonds; they are liquid at room temp.
Synthetic Polymers
•Fibers like wool and silk obtained from animals are proteins joined together by many amide linkages. •Two common classes of synthetic polymers are polyamides and polyesters. ex: wool and silk- polymers with many amide bonds
An Introduction to Nomenclature A. The IUPAC System of Nomenclature
•IUPAC stands for International Union of Pure and Applied Chemistry. •The IUPAC system of nomenclature provides a system of naming organic compounds. •Using the IUPAC system, each organic compound gets a unique and unambiguous name.
Interesting Alkenes in Food and Medicine
•Lycopene, the red pigment in tomatoes and watermelons, has 13 double bonds. •Lycopene is an antioxidant, a compound that prevents unwanted oxidation from occurring. •Diets containing high levels of antioxidants result in decreased risk of heart disease and cancer. •Tamoxifen is used in the treatment of breast cancers that require estrogen for growth.
Interesting Esters and Amides
•Many low molecular weight esters have pleasant odors: slide 36 •The amide melatonin is thought to induce sleep because it's production is increased by the body during the evening. •The ester benzocaine is the active ingredient in topical anesthetics. •The amide acetaminophen is a pain reliever in Tylenol.
Synthetic Polymers Focus on the Environment
•Many polymers do not degrade readily, and billions of pounds of polymers end up in landfills. •The lower a polymer' s recycling code (1-6), the easier it is to recycle the polymer to combat the waste problem. •PET has a recycling code "1", as it is the easiest to recycle, and is re-used as fleece clothing and carpeting. •Heating PET with H2O and acid returns the polymer to its monomer units, which serve as starting material for more PET.
interesting alcohols
•Methanol (CH3OH) is useful as a solvent and a starting material for plastics, but it is toxic due to its oxidation in the liver. •Ethanol (CH3CH2OH) is the alcohol present in alcoholic beverages, and it is formed from the fermentation of carbohydrate chains. •Ethylene glycol (HOCH2CH2OH), a diol, is the major component of antifreeze; it is sweet-tasting but extremely toxic. •Glycerol [(HOCH2 )2CHOH], a triol, is used in lotions, liquid soap, and shaving cream; it is also sweet-tasting, but nontoxic, so it can be used in food products. Carbohydrates are very long, alcohol-containing, and naturally occurring polymers, synthesized primarily by plants. •Starch is the main carbohydrate in seeds and the roots of plants, and it can be metabolized by humans into glucose. •Cellulose, the major component of wood, cotton, and flax, gives rigidity to plants, however, it cannot be metabolized by humans.
Focus on Health & Medicine A. The Metabolism of Methanol
•Methanol is oxidized into formaldehyde and then to formic acid by the same enzymes as ethanol. •Both of these compounds are extremely toxic, and consumption of methanol leads to decreased blood pH, blindness, and finally death.
Focus on the Environment Fossil Fuels
•Natural gas is composed mostly of methane, which burns in the presence of oxygen, releasing energy for cooking and heating. •Petroleum is a complex mixture of compounds that must be refined to separate it into usable fractions. •Gasoline (C5H12-C12H26), kerosene (C12H26- C16H34), and diesel fuel (C15H32-C18H38) are some of the products of petroleum refinement. •Other portions are used to make plastics, drugs, fabrics, dyes, and pesticides.
Synthetic Polymers Nylon—A Polyamide
•Nylon is a condensation polymer, formed when two monomers come together, releasing water.
Simple Alkanes D. Bond Rotation and Skeletal Structures for Acyclic Alkanes
•Rotation can occur around carbon-carbon single bonds. •The zigzag arrangement of atoms is the most stable, because it avoids crowding. •The skeletal structures of alkanes follow the same zigzag pattern.
Interesting Carboxylic Acids Skin Care Products
•Several skin care products purported to smooth fine lines contain a-hydroxy acids •These acids work by removing the outer, older layer of skin cells, revealing the healthier looking, new cells underneath.
Interesting Carboxylic Acids
•Simple carboxylic acids have foul or biting odors. •Formic acid (HCO2H) is responsible for the sting of some types of ants. •Acetic acid (CH3CO2H) is the sour-tasting component of vinegar; it can be made by air oxidation of ethanol when wine "goes bad". •Hexanoic acid [(CH3 (CH2 )4COOH)] has the foul odor of dirty socks and locker rooms.
Synthetic Polymers Focus on Health & Medicine
•Slowly degrading polyesters are useful in making sutures. •The mending tissue is held together for a length of time to heal, and then the sutures break down.
Focus on Health & Medicine A. The Metabolism of Ethanol
•When ethanol is consumed it is quickly absorbed in the stomach and small intestines. •In the liver, the enzymes alcohol and aldehyde dehydrogenase act as oxidizing reagents. •Consuming more ethanol than can be metabolized leads to a buildup of acetaldehyde, which is toxic.
Acid Base Reactions
• In an acid-base reaction, the acid donates a proton (H+ ) to the base. • Generally, when solutions of an acid and a base are combined, the products are a salt ion and water -
Drawing Lewis Structures
1. Find sum the valence electrons from all atoms in the polyatomic or molecule - if anion, add one electron for each negative charge - if cation, subtract one electron for each positive charge 2. The central atom is the least electronegative element that isn't hydrogen. Connect the outer atoms to it by single bonds 3. Fill the octets of the outer atoms 4. Fill the octet of the central atom 5. Total the number of electrons in the structure and compare it to step 1. - If there are too many electrons, the structure probably needs a double or triple bond. Add one and repeat steps 3-5 until the electron totals match • Consider PCl3 . . . . . P . . Cl : . . . (5) + 3(7)= 26 e- 1. Find the sum of valence electrons of all atoms in the polyatomic ion or molecule ----- If it is an anion, add one electron for each negative charge ----- If it is a cation, subtract one electron for each positive charge 2. The central atom is the least electronegative element that isn't hydrogen. Connect the outer atoms to it by single bonds 3. Fill the octets of the outer atoms 4. Fill the octet of the central atom 5. Total the number of electrons in the structure and compare it to step 1. If there are too many electrons, the structure probably needs a double or triple bond. Add one and repeat steps 3-5 until the electron totals match . . . . . . : Cl - P - Cl : . . / . . : Cl : . . more examples in notebook
Write the systematic names for the given compounds. Spelling counts! . . . . . . . . Cl - P - Cl . . . . / . . . . Cl . . . . and . . O . . . . O . . / / / / As As // / // . . O . . O. . O . . . . . .
1. Phosphorus Trichloride 2. diarsenic Pentaoxide
Tetrahedral
109.5 degrees • Tetrahedral: 4 electron domains, 3 possible molecular geometries - 0 NB domains: tetrahedral - 1 NB domain: trigonal pyramidal - 2 NB domains: bent
Write the complete symbol, including mass number and atomic number, for each atom. an oxygen atom with 10 neutrons
18 O 8
11 Na
1s2 2s2 2p2 3s1
17 Cl
1s2 2s2 2p6 3s2 3p6
electron configuration for 54Xe
1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6
A 11.75 g sample of NaBr contains 22.34% Na by mass. Considering the law of constant composition (definite proportions), how many grams of sodium does a 9.35 g sample of sodium bromide contain?
22.34% x 9.35g = 2.088 rounded to 2.1 g Na
atomic number of Cu (Copper)
29
Write the complete symbol, including mass number and atomic number, for each atom. contain 15 electrons and 19 neutrons
34 P 15
atomic number of Br (Bromine)
35
atomic number of Kr (Krypton)
36
atomic number of Rb- (Rubidium)
37
Write the complete symbol, including mass number and atomic number, for each atom. contains 22 protons and 21 neutrons
43 Ti 22
Write the complete symbol, including mass number and atomic number, for each atom. a chromium atom with a mass number of 54
54 Cr 24
Write the complete symbol, including mass number and atomic number, for each atom. contains 28 protons and 30 neutrons
58 Ni 28
Mixture
A combination of two or more substances that are not chemically combined
Law
A description that predicts what happens, but does not explain how
mass
A measurement of the amount of matter in an object
homogeneous mixture
A mixture in which substances are evenly distributed throughout the mixture
heterogeneous mixture
A mixture that is not uniform in composition; components are not evenly distributed throughout the mixture
Metals and nonmetals can react with each other to form ions. Complete each statement.
A potassium atom loses one electron to form a +1 ion.A sulfur atom gains two electrons to form a -2 ion.
Element
A pure substance made of only one kind of atom
d= m/v d= 15.21/5.07 D= 3
A sample of metal has a mass of 15.21 g, and a volume of 5.07 mL. What is the density of this metal?
Theory
A scientist incorporates known proven facts and states that organisms are composed of cells
Compound
A substance made up of atoms of two or more different elements joined by chemical bonds
What is the pH of a 0.0400 M aqueous solution of KOH ? a. 12.60 b. 10.30 c. 4.00 d. 1.40
A.
Simple Alkanes
A. Acyclic Alkanes Having Fewer than Five Carbons •Methane is a one-carbon alkane.- tetrahedral •Ethane is a two-carbon alkane. •Propane is a three-carbon alkane. •The following two representations of propane are equivalent: ----•The bends in a carbon chain don't matter when it comes to identifying different compounds. •Butane is a four-carbon alkane. Four carbons can be a straight-chain or branched-chain alkane. Butane and isobutane are isomers of each other. •Isomers are two different compounds with the same molecular formula. •Constitutional isomers differ in the way the atoms are connected to each other. •Another example of constitutional isomers: •As the number of C atoms increases, the number of possible isomers increases. •Pentane is a five-carbon alkane with three isomers:
Drawing organic molecules A. Condensed Structures
A. Condensed Structures In a condensed structure, all of the atoms are drawn in, but the two-electron bond lines and lone pairs on heteroatoms are generally omitted. ----•A carbon bonded to 3 H' s becomes CH3 . ----•A carbon bonded to 2 H' s becomes CH2 . •Some bond lines can be drawn in for effect or to show specific bonding. ----•A carbon bonded to 1 H becomes CH •Identical groups can be condensed further:
A 6.73g sample of calcium sulfide was decomposed into its constituent elements, producing 3.74 g of calcium and 2.99 g of sulfur. Which of the statements are consistent with the law of constant composition (definite proportions)? a. The mass percentage of calcium plus the mass percentage of sulfur in every sample of calcium sulfide equals 100%. b. The mass ratio of SS to CaCa in every sample of calcium sulfide is 0.80. c. The ratio of calcium to sulfur will vary based on how the sample was prepared. d. Every sample of calcium sulfide will have 44.4% mass of sulfur. e. Every sample of calcium sulfide will have 3.74 g of calcium.
A. The mass percentage of calcium plus the mass percentage of sulfur in every sample of calcium sulfide equals 100%. B. The mass ratio of SS to CaCa in every sample of calcium sulfide is 0.80. D. Every sample of calcium sulfide will have 44.4% mass of sulfur.
Suppose there are two known compounds containing the generic elements X and Y. You have a 1.00 g sample of each compound. One sample contains 0.35 g of X and the other contains 0.45 g of X. Identify plausible sets of formulas for these two compounds. a. X2Y and X3Y b. XY3 and XY4 c. X2Y4 and X3Y4 d. XY and X3Y e. X3Y and X4Y f. XY and X2Y g. X4Y2 and X3Y
A. X2Y and X3Y C.X2Y4 and X3Y4 G.X4Y2 and X3Y
Carbonyl Containing Compounds: Physical Properties
Aldehydes and ketones have higher boiling points than similar hydrocarbons because: •they are polar molecules •they have stronger intermolecular forces than alkanes and alkenes Aldehydes and ketones have lower boiling points than similar alcohols because: •they do not have an O—H bond •therefore, they cannot have intermolecular hydrogen bonding •thus, they have weaker intermolecular forces than alcohols •Aldehydes and ketones are soluble in organic solvents. •Those molecules with 6 C's or less are soluble in water. •Those molecules with 7 C' s or more are insoluble in water.
elements in alkali metals
Alkali Metals: highly reactive metals, low melting points, lowest ionization energy of any group • Na and K known since ancient times, isolated in 1807 • Na+ : Major component of blood plasma • K + : Major component of intracellular fluids • The difference in the concentrations of these ions creates and electric potential that can be used to do work (nerve function • Li isolated in 1808. No known biological function • Lithiated lemon soda (7up) was sold from the late 1920s to the early 1950s (at which point the lithium salt was removed) • Lithium salts were found to be effective antipsychotics in the 1950's and were approved for use in the 1970s. They are still the most effective drug to treat manicdepressive or bipolar disorder (Eskalith) despite their high toxicity
Group and trends of Alkali metals
Alkali metals are soft, metallic solids • The name comes from the Arabic word for ashes • They are found only in compounds in nature, not in their elemental forms • They have low densities, boiling points, and ionization energies
Elements in Alkaline Earth Metals
Alkaline Earth Metals: found as sulfates and carbonates in mineral deposits • Be: Used in alloys to improve strength and corrosion resistance of other metals. Emeralds are obtained from the mineral source of Be (beryl) • Ca: 5th most abundant element on earth, Compounds are widely used building materials: concrete, cements, bones, and teeth. Regulation of Ca2+ is necessary for nerve function • Mg: 6th most abundant element on earth. Used in alloys as a strong, light, building material. Mg2+ is the active metal in chlorophyll • Radium: isolated by the Curies, used to treat certain cancers
Alkaline Earth Metals
Alkaline earth metals have higher densities and melting points than alkali metals. • Their ionization energies are low, but not as low as those of alkali metals • Beryllium does not react with water and magnesium reacts only with steam, but the others react readily with water. • Reactivity tends to increase as you go down the group
Introduction to Alkanes
Alkanes are hydrocarbons having only C-C and C-H single bonds. •Alkanes that contain chains of C atoms but no rings are acyclic alkanes and have the general formula CnH2n+2 . •Acyclic alkanes are called saturated alkanes because they have the maximum number of H atoms per C atom.
Lecture 11
Alkanes, Alkenes, Alkynes, and Benzenes
Alkenes and Alkynes
Alkenes and alkynes are two families of organic molecules that contain multiple bonds. •Alkenes are compounds that contain a carbon− carbon double bond. •Alkenes have the general formula CnH2n . •Alkynes are compounds that contain a carbon− carbon triple bond. Alkynes have the general formula CnH2n-2 •Alkenes and alkynes have low melting and boiling points, and are insoluble in water. •Alkenes and alkynes are composed of nonpolar bonds. •Their physical properties are like those of alkanes. •They are called unsaturated hydrocarbons because they contain fewer than the maximum number of H atoms per C. •The multiple bond is always drawn in a condensed structure.
Pure Substances: Compounds
All heteroatomic molecules: diatomic triatomic or polyatomic.
common ions- cation charge
Cation Charge: The charge of a cation from the representative elements is the same as the family number. The name of a cation is simply the name of the element. Examples: Na+ = sodium ion Mg2+ = magnesium ion
Atoms subatomic particles
All of the experiments that led to the discovery of the subatomic particles depended on radioactivity- the spontaneous emission of radiation given off by "heavy" atoms to achieve a more stable nucleus • Discovered by Henri Becquerel in the late 1800's, further explored by Marie and Pierre Curie and Irene Joliat-Curie • Ernest Rutherford separated radiation into three types in the early 1900's: --- Alpha radiation (α) Large, positively charged particles, analogous to a helium nucleus ---- • Beta radiation (β): small negatively charged particle, analogous to an electron ----- • Gamma radiation (γ): uncharged, high energy rays, analogous to x-rays
The volume of water in the beaker can be determined by first determining the mass of the water, then dividing by its density. mass of water = 423.35 g - 33.81g = 389.54g. We know from above that the beaker can hold about 389.54g of a liquid, be it water or mercury. The mass of mercury can be calculated by multiplying the volume of the mercury by the density of mercury. Use the unrounded value from above to prevent rounding errors. 389.54g x 13.5 g/mL = 5258.79g. Total mass = beaker mercury = 33.81g - 52588.79g=
An empty beaker weighs 33.81 g. When completely filled with water, the beaker and its contents have a total mass of 423.35 g. What volume does the beaker hold? Use 𝑑=1.00 g/mL as the density of water. How much would the beaker and its contents weigh if it was completely filled with mercury? The density of mercury is 𝑑=13.5 g/mL.
Hypothesis
An entomologist guesses, but has not verified, that gray moths survive best on gray tree trunks
Theory
An explanation that has been tested and verified
Hypothesis
An untested explanation based upon observation or known facts
common ions (anions)
Anions: The charge of an anion from the representative elements is equal to the family number minus eight. The name of an anion is the root name of the element plus the suffix -ide. Examples: Cl- = chloride ion O2- = oxide ion
Matter
Anything that takes up space and has mass
Determine the chemical symbol for the neutral element corresponding to the electronic configuration. Use proper formatting; letter case matters: 1s²2s²2p⁶3s²3p³
Ar (argon)
greatest to least 1. 2.3x10^5 2. 53000 3. 3.7x10^-2 4. 9.0x10^-6 5. 7.9x10^-6
Arrange the values according to magnitude from greatest to least 53000 7.9x10^-6 9.0x10^-6 2.3x10^5 3.7x10^-2
the periodic law
Atoms with similar properties appear in groups or families (vertical columns) on the periodic table. • They are similar because they all have the same number of valence (outer shell) electrons, which governs their chemical behavior.
What is the pH of a 0.0200 M aqueous solution of HBr ? a. 1.00 b. 1.70 c. 2.30 d. 12.30
B
Determine the number of valence electrons for each of the atoms. Enter each answer as a numeral. For example, if an atom has two valence electrons, enter the number 2. B F Mg Ne
B: (boron) 7 F:7 Mg: 2 - 1s² 2s²2p⁶ 3s² Ne: 8 - 1s2 2s2 2p6
Determine the number of electrons lost or gained when each atom forms an ion:
Be: Loses 2 electrons. Se: Gains 2 electrons. I: Gains 1 electron. As: Gains 3 electrons P: gains 3 electrons
Write the name of the compound BrCl5? Spelling counts.
Bromine Pentachloride
What is the conjugate base of HPO4 2- ? a. H3PO4 b. H2PO4 1- c. PO4 3- d. HPO3 2-
C
The image depicts a famous scientific experiment Who performed this experiment?a.Ernest Rutherford b. J.J. Thompson c. Robert Millikan d. Niels Bohr What was determined from this experiment? a. That atoms have a positive nucleus. b. The existence of neutrons. c. The charge of an electron. d. That mass is conserved in chemical reactions.
C. Robert Millikan c. the charge of an electron
What volume of oxygen is required to burn 0.556 L of propane assuming both gases are measured at the same temperature and pressure?
C2H8 + O2 -> CO2 + H2O balanced equation: C3H8 + 5O2 -> 3CO2 + 4H2O 0.556L C3H8 ( 5 O2 / 1C3H8) = 2.78 L OF OXYGEN REQUIRED
C4 H8 - combustion reaction Butane gas combustion in air
C4 H8 (g) + O2 (g) -> CO2 (g) + H2O (g) balanced equation: C4H8 + 6O2 -> 4 CO2 + 4 H2O
examples of... Properties of Organic Compounds B. Solubility
CH3CH2CH2CH2CH2CH3 hexane •Small nonpolar molecule •No O or N present •H2O insoluble CH3CH2—OH ethanol •Small polar molecule •O atom present •H2O soluble cholesterol •Very large molecule •O atom present •Too many nonpolar C—C and C—H bonds •H2O insoluble
Aldehyde
CHO
Give the systematic name for each compound. Spelling counts. CIF3 Cl2O7
CIL3: chlorine Trifluoride Cl2O7: Dichlorine heptoxide
Significant Figures in Calculations
Calculations involving measurement can only be as accurate as the least accurate measurement. Answers have to be rounded to reflect the actual amount of precision (and uncertainty) present. • Multiplication and division: Round to the same number of digits as the measurement with the fewest significant figures • Addition and Subtraction: Round to the same decimal place as the measurement with the fewest decimal places. • Some numbers (such as conversion factors) are considered to be exact numbers, with no uncertainty (ex. 1 m = 100 cm) and thus are not considered when rounding answers.
Carboxylic Acids, Esters, and Amides
Carboxylic acids are organic compounds containing a COOH (carboxyl) group. •Carboxylic acids are abbreviated as RCOOH or RCO2H.
Carboxylic Acids, Esters, and Amides: Structure and Bonding
Esters are carbonyl compounds that contain an OR' (alkoxy) group bonded to the carbonyl C atom. •Esters are abbreviated as RCOOR′ or RCO2R′. Amides are carbonyl compounds that contain a N atom bonded to the carbonyl C. Amides are classified based on the number of C atoms bonded to the N atom •A primary (1 o) amide contains 1 C—N bond. •It is abbreviated as RCONH2 . •A secondary (2 o) amide contains two C—N bonds, and is abbreviated RCONHR′ •A tertiary (3 o) amide contains three C—N bonds, and is abbreviated RCONHR′ 2 •Carboxylic acids, esters, and amides all contain an acyl (RCO) group bonded to a N or O atom. - all have a dipole •The carbonyl carbon is trigonal planar, so all bond angles are 120o. •O is more electronegative than C, so the carbonyl group is polar. •The carbonyl O is e− rich (δ− ) and the carbonyl C is e− poor (δ+ ).
Measurement: Number and Units (Covered in Lab) Numbers used can be exact or measurements
Exact numbers represent ratios and constants and are considered to have infinite significant figures. • 1 cm is exactly 10 mm Measurements are ALWAYS expressed to the correct number of significant figures • The precision of a measurement is indicated by the number of significant figures
The Art of Deduction: Stable Electron Configurations
Fact: Noble gases, such as helium, neon, and argon are inert, they undergo few if any, chemical reactions. Theory: The inertness of noble gases results from their electron structures; each (except helium) has an octet of electrons in its outermost shell. Deduction: Elements become less reactive when they alter their electron structures to that of a noble gas.
families ve periods
Families: • Columns of elements are called groups or families. • Elements in each family have similar but not identical properties. • For example, lithium (Li), sodium (Na), potassium (K), and other members of family IA are all soft, white, shiny metals. Periods: Each horizontal row of elements is called a period. • The elements in a period are not alike in properties. In fact, the properties change greatly across every given row. • The first element in a period is always an extremely active solid. The last element in a period, is always an inactive gas.
vitamin A
Focus on Health and Medicine A. Vitamin A •Vitamin A—retinol—is an essential component of the vision receptors in the eyes. •It also helps to maintain the health of the mucous membranes and the skin. •Vitamin A is a very large, mostly nonpolar molecule with only one OH group, making it a fat-soluble vitamin. fat-solube vitamins are readily is stored in the liver and fatty tissue
Carbonyl Containing Compounds Interesting Aldehydes and Ketones
Formaldehyde (CH2═O) is the simplest aldehyde: •It is the starting material for synthesis of resins and plastics. •It is sold as formalin, a 37% aqueous solution used to preserve biological specimens. Acetone [(CH3 )2C═O] is the simplest ketone: •It is an industrial solvent and a starting material for organic polymers. •It is produced in the breakdown of fatty acids in the body. •Unusually high levels are found in diabetic patients. Cinnamaldehyde, the major component of cinnamon bark: slide 13 Vanillin, the primary component of the extract of the vanilla bean: slide 13 Citral, the characteristic odor of lemon grass, used in perfumery and in synthesis of vitamin A: slide 14 Citronellal, the odor of citronella candles, used to repel mosquitoes: slide 14
Avogadro's Number and the Mole Formula mass. atomic masses. molecular mass
Formula mass is the average mass of a formula unit relative to that of a carbon-12 atom. It is simply the sum of the atomic masses for all atoms in a formula. If the formula represents a molecule, often the term molecular mass is used
Introduction
Four families of compounds that contain a C atom singly bonded to O, S, or X (F, Cl, Br, or I) are: 1. Alcohols, which contain an OH (hydroxyl) group. 2. Ethers, which have two alkyl groups bonded to an O atom. 3. Alkyl halides, which contain a halogen atom X (X = F, Cl, Br, or I) 4. Thiols, which contain a SH (sulfhydryl) group
Odd Electron Molecules: ( exceptions to lewis model) examples in notebook
Free Radicals An atom or molecule with an unpaired electron is known as a free radical.
noble gases
Group 18 of the periodic table
alkaline earth metals
Group 2 A of the periodic table
Group trends: Alkali metals
Group Trends: Alkali Metals • Their reactions with water produce heat -----• 2M + 2H2O 2MOH(aq) + H2(g) • They react with hydrogen to form hydrides, and sulfur to form sulfides • Alkali metals (except Li) react with oxygen to form peroxides • K, Rb, and Cs also form superoxides • They produce bright colors when placed in a flame
What are the diatomic elements?
H2, N2, O2, F2, Cl2, Br2, I2
Strong acids are
HCl, HBr, HI, HNO3, H2SO4, HClO4 - include H at the beginning
Group 7 of the periodic table
Halogens (salt formers) - F Cl Br I At
Metalloids
Have properties intermediate to metals and non-metals • Example: Silicon ----- • Luster -----• Brittle ------• Semi-conductor
practice - Solid mercury(II) oxide decomposes when heated into elemental mercury (a liquid) and oxygen.
HgO (s)----> Hg(l) + O2 (g) not balanced to balance it 2HgO---> 2Hg + O2
sig fig practice
How many sig figs does each measurement/ answer have? • 1.0020 • 160,200 • 0.000400 • 5000 • 0.00107 • 8.500 • 2.52 + 6.0 - 0.00458 = 8.51542 (calculated answer) • 0.005 x 7.43 x 10.0 = 0.3715 (calculated answer • (3.56 x 10-7 )/(0.012 x 105 ) = 2.96666667 x 10-11 (calculated)
Functional Groups A. Hydrocarbons
Hydrocarbons are compounds that contain only carbon and hydrogen. --•Alkanes have only C-C single bonds and no functional group. --•Alkenes have a C-C double bond as their functional group. ---•Alkynes have a C-C triple bond as their functional group. -•Aromatic hydrocarbons contain a benzene ring, a six-membered ring with three double bonds.
Measurements in Calculations (Covered in Lab)
It is often necessary to adjust the units of measurements as we do calculations to make the numbers involved easier to work with. • In addition to making the numbers more understandable, this gives us the opportunity to introduce the DIMENSIONAL ANALYSIS METHOD which we will continue using throughout the course. • Use conversion factors to convert one unit to another. 2.2 lbs = 1 kg • A 150 lb person weighs how much in kg? • 𝐺𝑖𝑣𝑒𝑛 𝑢𝑛𝑖𝑡 × 𝑑𝑒𝑠𝑖𝑟𝑒𝑑 𝑢𝑛𝑖𝑡 / 𝑔𝑖𝑣𝑒𝑛 𝑢𝑛𝑖𝑡 = 𝑑𝑒𝑠𝑖𝑟𝑒𝑑 𝑢𝑛𝑖t
potassium chlorate (KClO3) decomposes into potassium chloride and oxygen gas
KClO3 (s) -> KCl (s) + O2 (g) balanced equation: 2KClO3 -> 2 KCl + 3O2
A neutral isotope has 49 neutrons and 36 electrons. Identify the element symbol of this isotope and determine the mass number and number of protons.
Kr mass number: 85 protons: 36
Determine the chemical symbol for the neutral element corresponding to the electronic configuration. Use proper formatting; letter case matters: 1s²2s²2p⁶3s²3p⁶4s²3d¹⁰4p⁶
Kr (krypton)
Law of Conservation of Matter
Lavoisier ex: 100.00 grams of mercuric oxide = 92.61 grams of mercury + 7.39 grams of oxygen
Name each compound and determine the charge on each ion in the compounds. Spelling counts.
Li 2 O name: Lithium Oxide Li charge: +1 O charge: -2 CaS name: calcium sulfide Ca charge: +2 S charge: -2
Strong bases are
LiOH, NaOH, KOH, RbOH, CsOH, Ca(OH)2, Sr(OH)2, Ba(OH)2 - end in OH NH3 is a base because it a proton acceptor
atomic number 12 what is chemical symbol?
Magnesium- Mg
covalent bonds
Many nonmetallic elements react by sharing electrons rather than by gaining or losing electrons. When two atoms share a pair of electrons, a covalent bond is formed. Atoms can share one, two, or three pairs of electrons, forming single, double, and triple bonds
Formulas and Names of Ionic Compounds
Many transition metals can exhibit more than one ionic charge. Roman numerals are used to denote the charge of such ions ex: Fe2+ = iron(II) ion Fe3+ = iron(III) ion Cu2+ = copper(II) ion Cu+ = copper(I) ion
The Periodic Law
Mendeleev understood the 'Periodic Law' which states: • When arranged by increasing atomic number, the chemical elements display a regular and repeating pattern of chemical and physical properties.
Measurement: Number and Units (Covered in Lab)
Metric System Units ex: Base Units: Celcius, grams, meters, liters, joules • English (Common) System Units ex: Miles, yards, inches, feet, pounds, degrees Fahrenheit
An Introduction to Nomenclature B. Naming New Drugs
Most drugs have three names: •Systematic: The IUPAC name—e.g., 2-[4-(2-methylpropyl)phenyl]propanoic acid •Generic: The official, internationally approved name of the drug—e.g., ibuprofen •Trade: The name assigned by the company that manufactures the drug—e.g., Motrin or Advil
Identify these elements based on their locations in the periodic table. Give the symbol, not the name. period 2, group 15 (5A)
N (Nitrogen)
Determine the chemical symbol for the neutral element corresponding to the electronic configuration. Use proper formatting; letter case matters: 1s²2s²2p³
N (nitrogen)
practice Write and balance the following equations - Dinitrogen pentoxide combines with liquid water to produce aqueous nitric acid (HNO3 ).
N2O5(g) + H2O(l) -----> HNO3 N 2 =2 N 1 x2 =2 O 5 +1 =6 O 3 x2 =6 H 2 =2 H 1 x 2=2
name the compounds
NCI3: Nitrogen trichloride P4O6: tetraphosphorus hexaoxide BrCl:Bromine chloride SF4: Sulfur tetrafluoride CIO2: chlorine dioxide
Amide
NH2 -1
Determine the formula for sodium oxide.
Na 2 O
Sodium Reacts with Chlorine, Theory
Na+ ions and Cl- have opposite charges and attract each other. The resulting attraction is an ionic bond Ionic compounds are held together by ionic bonds and exist as crystal lattice
Sodium Sulfate (Na2SO4) and calcium chloride CaCl2 react in solution
Na2SO4 (aq) + CaCl2 (aq) -> 2 NaCl (aq) + CaSO4 (s) double displacement reaction
atomic number 10 what is chemical symbol?
Neon- Ne
atomic number 7 what is chemical symbol?
Nitrogen- N
significant figures
Non-zero numbers are always significant • 123.4 • Zeros between non-zero numbers are always significant • 10,023 • Zeros not preceded by a non zero number are not significant • 0.000123 • Zeros at the end of a number are sometimes significant. - If the zeros are at the end of a number and to the right of a decimal, they are significant. • 2125.00 - If the zeros are at the end of a number and to the left of the decimal, they are not significant. The only exception to this rule is if a decimal appears after the last zero -50,000 • 50,000.
Pure Substances: elements
Note: Be familiar with names and symbols of common elements (practice problems available at end of chapter) • Single atoms: monoatomic (most metallic elements) • Homoatomic molecules: diatomic, triatomic, and polyatomic
periodic table
The arrangement of the modern periodic table is based on significant contributions from Dmitri Mendeleev (1869), Lothar Meyer (1869), and Henry Moseley (1913) • Mendeleev and Meyer independently came to the same conclusion about how elements should be grouped, based on their properties • Moseley accurately determined the atomic numbers of the elements, fixing the issues with the previous periodic tables (based on atomic weights) ----- • Bombardment of atoms with high energy electrons causes them to emit Xrays of specific frequencies. When assigned whole numbers, these frequencies correspond with the number of protons in the nucleus.
Acid-Base Properties of Salt Solutions
The combined effects of cations and anions in solution are: 1. An anion that is the conjugate base of a strong acid will not affect the pH 2. An anion that is the conjugate base of a weak acid will increase the pH 3. A cation that is the conjugate acid of a weak base will decrease the pH 4. Cations of the strong Arrhenius bases will not affect the pH 5. Other metal ions will cause a decrease in pH
bond polarity
The difference in electronegativity between two bonded atoms can be used to determine the type of bond. Use the adjacent table as a rule of thumb.
alkane nomenclature
The names of alkanes with substituents have three parts: •The parent name indicates the number of C's in the longest continuous carbon chain in the molecule. •The suffix indicates what functional group is present. •The prefix tells the identity, location, and number of substituents attached to the carbon chain.
Fission
The splitting of an atomic nucleus to release energy. Nuclear fission is the type of reaction carried out in nuclear reactors • Bombardment of the radioactive nuclide with a neutron starts the process. • Neutrons released in the transmutation strike other nuclei, causing their decay and the production of more neutrons • This process continues in what we call a nuclear chain reaction If there are not enough radioactive nuclides in the path of the ejected neutrons, the chain reaction will die out. • Therefore, there must be a certain minimum amount of fissionable material present for the chain reaction to be sustained: critical mass
What are the group numbers and the generic outer electron configurations for a neutral atom with the given Lewis symbols? . . x . . . and . . . x . . .
There are 5 electrons around this symbol so it\'s a 5A element with an electron configuration of ns2np3. (The element could be N, P, As, Sb, or Bi.) There are 6 electrons around this symbol so it\'s a 6A element with an electron configuration of ns2np4. (The element could be O, S, Se, Te, or Po.)
Structure and Properties of Ethers A. Physical Properties
These facts give ethers: •stronger intermolecular forces than alkanes •weaker intermolecular forces than alcohols As a result, ethers of comparable size and shape tend to have: •higher melting and boiling points than hydrocarbons •lower melting and boiling points than alcohols •Ethers are soluble in organic solvents. •Low molecular weight ethers (5 C's or less) are soluble in water, as water can hydrogen bond to the ether's O atom. •Higher molecular weight ethers (6 C's or more) are not soluble in water.
shapes of organic molecules draw 3-d
To draw a 3D tetrahedron on a page, we use: •A solid line for bonds in the plane •A wedge for a bond in front of the plane •A dashed line for a bond behind the plane -Every carbon with four single bonds is tetrahedral -Every carbon with four single bonds is tetrahedral -•Oxygen is attached to 2 atoms and has 2 lone pairs, making its shape bent.
formulas and names of ionic compounds
To name binary ionic compounds, simply name the ions. ex: NaCl = sodium chloride MgO = magnesium oxide
Carbonyl Containing Compounds
Two broad classes of compounds contain a carbonyl group:
Mixtures
Two or more substances that can be separated by physical means, i.e., filtration, distillation, chromatography, etc. - Homogeneous Mixtures: Same concentration or percentage of each substance throughout. Uniform appearance and properties ex: Kool-Aid in water, Air, Alloys: steel, jewelry - Heterogeneous Mixtures: properties and appearance are not uniform throughout the sample. ex: Sand, Italian Salad Dressing, concrete, milk
Shapes of organic molecules VSEPR THEORY
VSEPR theory: The most stable arrangement keeps the groups on a central atom as far away from each other as possible. •An atom surrounded by two groups is linear and has a bond angle of 180o. -An atom surrounded by three groups is trigonal planar and has a bond angle of 120o. - •An atom surrounded by four groups is tetrahedral and has bond angles of 109.5o.
intermolecular forces-cont
Van der Waal's forces - dipole-dipole ----ion-dipole - London dispersion Hydrogen bonding
Focus on Health and Medicine
Vitamins are organic compounds needed in small amounts for normal cell function. •The body cannot synthesize these compounds; they must be obtained in the diet. •A fat-soluble vitamin dissolves in an organic solvent but is insoluble in water. •A water-soluble vitamin dissolves in water. •Fat-soluble vitamins have many nonpolar C-C and C-H bonds and few polar functional groups. •Water-soluble vitamins have many polar bonds.
atomic orbits - name of them...
We define the orbital size and shape to have a 90% chance of containing the electron (90% of the total electron density). • s orbitals: are spheres, 1s is smaller than 2s which is smaller than 3s ...
19.3g = m/3.40 cm cubed so 19.3g x3.40cm= 65.688
What is the mass, in grams, of a pure gold cube that has a volume of 3.40 cm^3? density for gold is 19.3g/cm cubed formula: 19.3g/1 cm cubed
Volume relationships in Chemical equations Law of Combined Volumes
When all measurements are made at the same temperature and pressure, the volumes of gaseous reactants and products are in a small whole-number ratios. ex: hydrogen gas (three volumes) + Nitrogen gas (one volume) = Ammonia gas (two volumes)
I n 1808, John Dalton proposed a series of statements regarding the atom that became known as Dalton's postulates or Dalton's atomic theory. Since Dalton's original proposal, some of the statements have been updated or changed due to new discoveries. Which of the statements was not a part of Dalton's original atomic theory? a. Matter is comprised of small particles called atoms. b. Different elements have atoms of different masses and properties. c. Atoms cannot be created or destroyed in a chemical reaction. d. Atoms of the same element have the same size, mass, and structure. e. All four statements are part of Dalton's original atomic theory.
e. All four statements are part of Dalton's original atomic theory.
Give the full electron configuration for sulfur.
electron configuration: 1s2 2s2 2p6 3s2 3p4
what is the maximum number of electrons in the n= 3 level
electrons 18
A neutral isotope has a mass number of 65 and 36 neutrons. Identify the element symbol of this isotope and determine the number of protons and electrons.
element symbol: Cu protons: 29 electrons: 29
practice • Calculate the number of oxygen atoms in 0.25 moles of calcium nitrate (Hint: all stoichiometry conversions, such as the conversion of moles to atoms mentioned above can be solved via the dimensional analysis method you have already learned. What conversion factors will you need to solve this problem?)
equation you need: 1 mol = 6.022x10^23 calcium nitrate- NO3^- 0.25mol Ca (NO3)2 (6 mol O / 1 mol Ca (NO3)2 (6.02x10^23 atoms of O/ 1 mol O) = 9.0x10^23 atoms of O
periodic table and how to label elements
first #- atomic number, Z symbol- chemical symbol #- atomic mass (weight avg)
1. observation of physical world 2. create hypothesis about observation 3. test consequences of hypothesis 4
four basic steps of the scientific method in the correct order, from start to finish.
what does atomic orbital d look like
four leaf clover
more acidic
high to low ? lemon juice cola, vinegar wine tomatoes banana black coffee rain saliva milk
Solutions
homogeneous mixtures • Solutions are homogenous mixtures ----- Solute: part of solution present in lower concentration ---- Solvent: part of solution present in higher concentration • In general solubility of a solute can be increased by: ---- increasing the temperature ---- decreasing the particle size - stirring • Three general classes: ---- Unsaturated ---- Saturated ---- Supersaturated
solutions are...
homogenous mixtures - Solute: part of solution present in lower concentration - Solvent: part of solution present in higher concentration • In general solubility of a solute can be increased by: - increasing the temperature - decreasing the particle size - stirring • Three general classes: - Unsaturated - Saturated - Supersaturated
the element symbol and mass number is given for each of the atoms. using the element sym. each atoms entry in periodic table can be found. the periodic table entry for each element lists the element symbol and atomic number. the atomic number is equal to the number of protons in the nucleus of an atom. because a neutral atom has the same number of electrons as protons, the atomic number also specifies the number of electrons present. the mass number is equal to the number of neutrons in the nucleus of the atom Mass number = number of protons + number of neutrons Atomic number = number of protons = number of electrons Mass number = number of protons + number of neutrons,
how to find proton neutron and electrons
more basic
human blood, tears egg whites ..................
lewis structure practice
in notebook
practice
in notebook
practice example • In addition to the usual units of pressure, lb/in2 (psi) is a common unit in the English system. If 1 atm.=14.7 (psi), what is a pressure of 91.5 (psi) in expressed in mmHg?
in notebook
Pr is it a noble gas, representative element (main-group element), transition element, Inner transition element (lanthanide/actinide series)
inner transition element
U is it a noble gas, representative element (main-group element), transition element, Inner transition element (lanthanide/actinide series)
inner transition element
hydrogen bonding
intermolecular attraction that occurs between a hydrogen H, atom in a polar bond (H bonded to N, O, or F) and non-bonding electron pair on a nearby electronegative atom/ion (usually N, O or F) - Hydrogen has no inner-core electrons, so the exposed proton of the nucleus is able to get much closer to a neighboring atom/ion resulting in a, unusually strong intermolecular bond. - Hydrogen bonding accounts for the unusual properties of water • One of the only substances that has a solid phase that is less dense than its liquid phase (more stability) - Stability given by hydrogen bonding allows for a higher than average boiling point and a lower freezing point • Large number of intermolecular interactions allow water to act as a solvent for a wide variety of substances.
intermolecular forces- ion dipoles
ion-dipole interactions are generally stronger than dipole-dipole interactions the more polar the molecule, the higher its boiling point, more molecules will stay together
Describing Matter
is described on the submicroscopic level by the atomic theory/model (Particulate Model of Matter)
Bohr Model Limitations
it only works for hydrogen without the introduction of multiple constants that increase with each successive element. - • This model was exciting but fails to explain the line spectra for anything but hydrogen. • Other atoms have more complex line spectra with lines very close to one another indicating similar energy changes.
match each observation to the law it illustrates laws: law of conservation of mass law of definite proportions (law of constant composition) Law of Multiple Proportions observations: - when 3 g of canon reacts with 8 g of oxygen, 11 g of carbon dioxide is produced. - the C:O mass ration of one compound is exactly double that of another compound - burning 10 g of propane produces twice as much carbon dioxide as burning 5 g of propane - the C:O mass ratio of a particular compound is the same, regardless of the size or source of the sample
law of conservation of mass---- when 3 g of canon reacts with 8 g of oxygen, 11 g of carbon dioxide is produced. law of definite proportions (law of constant composition)-----the C:O mass ratio of a particular compound is the same, regardless of the size or source of the sample ------ burning 10 g of propane produces twice as much carbon dioxide as burning 5 g of propane Law of Multiple Proportions-----the C:O mass ration of one compound is exactly double that of another compound
Molecular shapes
linear - 180 degrees trigonal planar- 120 degrees tetrahedral- 109 degrees trigonal bipyramidal- 90 degrees and 120 degrees octahedral- 90 degrees and 90 degrees
What is the name of the compound with the chemical formula MgCl2? Spelling counts.
magnesium chloride
What is the name of the compound with the chemical formula MgO? Spelling counts.
magnesium oxide
In the combustion of hydrogen gas, hydrogen reacts with oxygen from the air to form water vapor. hydrogen + oxygen ---> water If you burn 26.8 g of hydrogen and produce 2.40×10^2g (240g) of water, how much oxygen reacted?
mass of oxygen: 240g-26.8g= 213.2g
metal or nonmetal Cu
metal
metal or nonmetal Mg
metal
metal or nonmetal Zn
metal
characteristics of organic compounds
methane is the main component of natural gas ethanol- is the alcohol present in alcoholic beverages. capsaicin- is the responsible for the spiciness of peppers, and is used for tropical pain-relief medicines caffeine- is the stimulant found in coffee, tea, cola beverages, and chocolate 1. all organic compounds contain carbon atoms and most contain hydrogen atoms: ---- carbon always forms four covalent bond ----hydrogen always forms one covalent bond 2. carbon forms, single, double, or triple bonds to other carbon atoms. shares electrons 3. some compounds have chains of atoms and some compounds have rings 4. organic compounds may also contain elements other than carbon and hyrdogen --- any atom that is not carbon or hydrogen is called a Heteroatom ---- each heteroatom forms a characteristic number of bonds, determined by its location in the periodic table. •The common heteroatoms (N, O, F, Cl, Br, and I) also have nonbonding, lone pairs of e− , so that each atom is surrounded by an octet of e− . - •The most common multiple bond between carbon and a heteroatom is a carbon-oxygen double bond.
dipole-dipole interactions
molecules that have permanent dipoles are attracted to each other - the positive end of one is attracted to the negative end of the other and vice versa - these forces are only important when the molecule are close to each other. polar covalent bonds
chemical vocab
name of element chemical formula lewis formula molecular geometry
Add electron dots and charges as necessary to show the reaction of calcium and oxygen to form an ionic compound.
neutral atoms . . . Ca . . O . . . ions . . Ca 2+ . . O . . 2- . .
Isotopes are atoms of a particular element that contain a different number of...
neutrons
Kr is it a noble gas, representative element (main-group element), transition element, Inner transition element (lanthanide/actinide series)
noble gas
group 8 on periodic table
noble gases (rare gases) - He - Ne -Ar - Kr - Xe - Rn
metal or nonmetal Br
non metal
metal or nonmetal Ne
non metal
practice in notebook Practice • Write the conjugate acid of each of the following - HSO3 ' - HClO4 - F - H2S - PO4 3- PH4 + - CO HCO3 - • Write the conjugate base of each of the above • When lithium oxide dissolves in water the reaction turns basic from the reaction of the oxide ion in water. Write the reaction that occurs and identify the conjugate acid-base pairs
notebook
VSEPR Summary
on pp slide 13
London dispersion forces
or dispersion forces, are attractions between an instantaneous dipole and an induced dipole - for a helium atom: while the electrons in the 1s orbital of helium would repel each other (and, therefore, tend to stay far away from each other) it des happen that they occasionally wind up on the same side of the atom (instantaneous dipole) - at that instant, then, the helium atom is polar, with an excess of electrons on the left side and a shortage on the right side - another helium nearby, then, would have a dipole induced in it, as the electrins ont he left side of helium atom 2 repel the electrons in the cluod on helium atom 1 - these forces are present in all molecules, whether they are polar or non polar - The tendency of an electron cloud to distort in this way is called polarizability - (size and shape affect this force) - the shape of the molecule affects the strength of dispersion forces: --- long, skinny molecules (like n-pentane) tend to have stronger dispersions..... - the strength of dispersion forces tends to increase with increased molecular weight - larger atoms have larger electrons clouds which are easier to polarize - if two molecules are of comparable size and shape............
how many orbitals are in the n= 3 level
orbitals 9
Focus on Health & Medicine Common Penicillins Used Today
penicillin G amoxicillin
comparing intermolecular interactions graph
powerpoint
what type of alcohol is 1-propanol? CH3CH2CH2OH
primary
autoionization of water
pure water reacts with itself to form hydronium and hydroxide ions - • As we have seen, water is amphiprotic. • In pure water, a few molecules act as bases and a few act as acids • H2O (l) + H2O (l) →H3O+ (aq) + OH- (aq) • This is referred to as autoionization -- Neither charged molecule remains for long, the reverse reaction is very fast -- At room temperature only about 2 out of a billion water molecules are ionized at any given instant -• The equilibrium expression for this process is --------------Kc = [H3O+ ] [OH- ] • This special equilibrium constant is referred to as the ion-product constant for water, Kw . • At 25C, Kw = 1.0 x 10-14 • Thus: - In a solution where [H+ ] = [OH- ] the solution is neutral - In a neutral solution the [H+ ] = [OH- ] = 1.0 x 10-7 Acidic neutral basic
Ga is it a noble gas, representative element (main-group element), transition element, Inner transition element (lanthanide/actinide series)
representative element
Ge is it a noble gas, representative element (main-group element), transition element, Inner transition element (lanthanide/actinide series)
representative element
Ra is it a noble gas, representative element (main-group element), transition element, Inner transition element (lanthanide/actinide series)
representative element
Theory
scientists after many experiments explain conservation of mass by stating that matter is composed of atoms
what does atomic orbital s look like
shape of a ball
what does atomic orbital P look like
shape of dumbell
AB + C ----> CB + A
single displacement reaction
how many sublevels are in the n= 3 level
sublevels 3
Identify the atom with the ground-state electron configuration 3s23p1
symbol: Al Aluminum
intermolcular forces
the attractions between molecules are not nearly as strong as the intramolecular attractions that hold compounds together - intermolecular forces are strong enough to control physical properties ---- boiling/melting ----viscosities
Molarity equation
the number of moles of solute per liter of solution • Two solutions can contain the same compounds but be quite different because the proportions of those compounds are different. • Molarity is the most common way to measure the concentration of a solution. moles of solute molarity (M) = ---------------- volume of solution in Liters
organic chemistry
the study of compounds containing the element carbon - affect virtually every facet of lives - products such as clothes, foods, medicines, gasoline, refrigerants, and soaps, are composed almost soley of organic compounds - some organic compounds can be obtained directly from natural sources- cotton, wool, and silk - others can be synthetically produced- nylon and polyesters
Au is it a noble gas, representative element (main-group element), transition element, Inner transition element (lanthanide/actinide series)
transition element
Mo is it a noble gas, representative element (main-group element), transition element, Inner transition element (lanthanide/actinide series)
transition element
middle of periodic table
transition metals- (1B-8B)
false
true and false mass and weight both depend on gravity
false
true or false mass and weight are the same thing
true
true or false your mass on the moon is the same as your mass on the Earth
false
true or false your weight on the moon is the same as your weight on the Earth
law of definite proportions
• Berzelius (Sometimes called the Law of Constant Composition) • The relative amount of each element in a compound is constant. • Mass Spectroscopy • Elemental Analysis • Suppose we analyze 2.83 g of a compound of lead and sulfur and find that it consists of 2.45 g Pb and 0.380 g S. Calculate the mass percentages of lead and sulfur in the compound. • A 5.650 g sample of a compound containing the elements K, N, and O was found to contain 38.67% K and 13.86% N. Calculate the number of grams of each element present in the sample ex: 10.00g of lead + 1.55g of sulfur = 11.55g of lead sulfide 10.00g of lead + 3.00g of sulfur = 11.55g of lead sulfide + 1.45g of sulfur (leftovers) 18.00g of lead + 1.55g of sulfur = 11.55g of lead sulfide + 8.00 of lead (leftovers)
Names of Covalent Compounds
• Binary covalent compounds are named by using a prefix to denote the number of atoms. prefix and # of atoms: mono- 1 Di- 2 Tri-3 Tetra- 4 Penta-5 Hexa-6 Hepta-7 Octa- 8 Nona- 9 Deca- 10 • Binary covalent compounds have two names ---- 1. First name = prefix + name of 1st element (Note: If the first element has only one atom, the prefix mono- is dropped.) ----2. Second name = prefix + root name of second element + suffix -ide • Binary Covalent compounds are composed of two non-metal substances sharing electrons • Ionic compounds are composed of metal ions and nonmetal ions that are electrostatically attracted to each other • What is the compound type and name of the following? • CO2 , BeF2 , PCl3 , N2O4
Combined Gas Law
• Boyle's Law and Charles's Law can be combined into a single law: (PV / T)= k • This equation can be put into a more useful form: - Suppose a gas sample is initially at a pressure and temperature of P1 and T1 and has a volume of V1 - P1V1/T1=k" Now suppose the pressure and temperature are changed to some new values, represented by P2 and T2 and that the volume changes to a new value V2 --- P2V2/T2=k" Since both quotients are equal to the same constant they can be equal to each other giving us. --- P1V1/T1=P2V2/T2
Limiting Reactants- examples
• Bromine can be prepared by adding chlorine to an aqueous solution of sodium bromide. The reaction equation is: • 2 NaBr (aq) + Cl2 (g) Br2 (l) + 2 NaCl (aq) • How many grams of bromine are formed if a solution containing 25.0 g of aqueous NaBr and 25.0 g of Cl2 (g) are reacted. - Limiting reactant/Theoretical Yield: • A student performed this procedure and collected 30.0 g of Br2 . What was their percent yield?
STP
• Calculations involving gases often involve comparisons or measurements made at standard temperature and pressure (STP) which are 0 ˚C and 1 atm. - Temperatures in calculations involving gases MUST be converted to Kelvin - The units of pressure are usually dependent on the units of the constant being used. Standard pressure is equal to 1.00atm=760torr =760mmHg =101.325kPa - One mole of any ideal gas at STP occupies 22.4 L of space.
covalent bonds
• Covalent bonds are shown via Lewis Structures (Note: Lewis symbols=atoms, Lewis structures= compounds) • Shared electrons are indicated by lines. Each line denotes 2 electrons. • Hydrogen shares to get 2 electrons (noble gas configuration of He) and most other elements share to get 8 valence electrons (octet rule) H - H .. .. .. Cl - Cl .. .. ..
Measurement
• Data collected in the scientific method can be qualitative or quantitative • The quality of data can be judged by.... Repeatability/verifiability • Accuracy and Precision
Additional Types of Reactions single and double displacement
• Displacement (single replacement): A reaction in which an element reacts with a compound, displacing an element from it. ---- Ex.: a copper wire reacts with silver (I) nitrate, producing elemental silver and copper(II) nitrate • Double displacement (ionic): two ionic compounds rearrange in aqueous solution to produce two new ionic compounds ----- Ex: Calcium chloride and sodium acetate react in solution.
Molecular Shape and Molecular Polarity
• Earlier, we learned how to determine if a single bond is polar • Additional guidelines are needed to determine if a molecule is polar ---- - Dipoles are vectors: they have magnitude and direction ----- Vectors of equal magnitude and opposite direction cancel each other out ---- - Consider H2O and CO2 :
Volume Relationships in Chemical Equations WITH EX
• For gases, Avogadro's number of molecules of any ideal gas has a volume of 22.4 L. EXAMPLE: - Hydrogen combines with oxygen to form water under certain conditions. If 4.50 liters of hydrogen are combined with excess oxygen, how many molecules of water can be produced? 2H2 + O2 -> 2H2O 4.50L H2 ( 2 H2O / 2 H2 ) (6.02 X 10^23 molecules / 22.4 L ) = 1.21 z 10 ^ 23 molecules
Avogadro's Number and the Mole
• Formulas represent the ratio of atoms in a molecule and therefore the ratio of elements by mass as well. • These ratios are used clinically to determine the identity of unknown substances. ---- What is the percent composition of the elements in copper (II) sulfate pentahydrate, CuSO4 · 5H2O? molecular weight= 63.5+ 32.1 + 9(16) + 10 (1.01) = 249.7 Cu (63.5 / 249.7) x100 = 25.4% Cu S 32.1 / 249.7 x 100 = 12.9% of S O (9x 16) / 249.7 x 100 = 57.7% H 100- 57.7- 12.9 - 25.4= 4.00% ---- A white substance is found to contain 18% oxygen by mass. Could the white compound be cocaine, C16H20O3N?
Lewis Symbols
• G. N. Lewis developed a method of visually representing the valence electrons as dots around the symbol of an atom • Lewis symbols can be written for main group atoms and ions • Transition metal atoms and ions are more complicated are represented by another model • Draw the lewis symbols for .Be . . . F . . Al3+ 1s2 2s2 2p6 3+ .. ..Al .. } 3+ .. O2- ??????
covalent bonding
• G.N. Lewis: Atoms could also acquire noble gas configurations by sharing electrons with other atoms; called covalent bonds • Atoms in covalent bonds are held together because the nuclei are mutually electrostatically attracted to the negative charges between them
PRACTICE
• How many atoms of copper are there in 6.54g? • A reaction is supposed to produce 3.01 x 1023 molecules silver(I)nitrate. How much will this product weigh in grams? WORK IN NOTEBOOK
Stoichiometric Conversions EXAMPLES
• How many moles of oxygen would be needed to completely combust 0.756 moles of methane? • How many moles of magnesium oxide would be produced from the combination reaction of 2.57g magnesium and oxygen gas? • 100.0g of potassium chlorate decomposes into potassium chloride and oxygen gas. How many grams of oxygen are formed in this reaction? IN NOTEBOOK
Properties of Liquids- Surface Tension
• Surface tension results from the net inward force experienced by the molecules on the surface of a liquid -- Molecules at the surface pack closer together -- Surface tension for water at 20 ˚C is 7.29 x 10-2 J/m2 -- Surface tension for mercury is 4.6 x 10-1 J/m2 • The interaction of surface tension with another surface (ex. Water in a test tube) results in a meniscus. The directionality of the meniscus can tell you which type of force is dominant in a system. --Cohesive Forces: Intermolecular forces that bind a substance to itself (meniscus curves upwards) -- Adhesive Forces Intermolecular forces that bind a substance to a surface (meniscus curves downwards) ------• Capillary action (a substance flowing into a small diameter tube) is a result of dominant adhesive forces
Electronegativity info
• The amount of time that electrons spend around each nuclei is determined by their electronegativity. • Electronegativity is the ability of atoms in a molecule to attract electrons to themselves ---- On the periodic chart, electronegativity increases as you go from left to right across a row and from the bottom to the top of a column ---- Fluorine is the most electronegative element on the periodic table
Electronegativity
• The amount of time that electrons spend around each nuclei is determined by their electronegativity. • Electronegativity is the ability of atoms in a molecule to attract electrons to themselves ---- On the periodic chart, electronegativity increases as you go from left to right across a row and from the bottom to the top of a column ----- Fluorine is the most electronegative element on the periodic table Electronegativity is a measure of an atom's attraction for the electrons in a bond.
chemical reactions
• The arrow indicates that a reaction is taking place. Common words to describe the arrow are "yields" "decomposes into" "combines to form" "reacts to make" etc. ----- All reactions are theoretically reversible, and different types of arrows are used to indicate the degree to which we can observe reversibility in given conditions ----- - The conditions in which a reaction takes place (other than the states of matter of the reactants) is often indicated above and below the arrow. Examples of such conditions are catalysts, solvents, heat (∆), and pressure
Stoichiometry of balanced equations
• The coefficients in chemical formulas can be the ratio of atoms or molecules (submicroscopic) or they can be the mole ratio of elements or compounds (macroscopic) • New conversion factor mole ratio (from balanced chemical equation WORK IN NOTEBOOK
Brønsted-Lowry Acids and Bases
• The degree to which an acid or a base dissolves in water is related to their relative strength • Substances with negligible acidity do not dissociate in water. - Their conjugate bases are very strong • Strong acids are completely dissociated in water. - Their conjugate bases are quite weak. • Weak acids only dissociate partially in water. - Their conjugate bases are weak bases
Ideal Gas Law
• The ideal gas law can be rearranged to solve for Pressure (P), Volume (V), Number of moles (n), and Temperature (T, in K) • Gas Stoichiometry can be calculated using a balanced equation and the n value in the ideal gas law (or the relationship 1mol =22.4L) • Additional equations can be substituted into the ideal gas law to solve for a variety of different variables. Two examples are molecular weight (MW) and density (d)
Formula and Molecular Weights
• The mass of a compound can be determined by the addition of the average atomic weights (found on the periodic table) of each atom present in the compound. • Formula weight: term used to describe the masses of elements and ionic compounds --- FW of Sodium = atomic weight of sodium = 23.0 amu --- FW of sodium sulfide (mass of one formula unit, or Na2S) --------• 2 (atomic weight of Na) + (atomic weight of S) --------• 2 (23.0) + (32.1) = 78.1 amu • Molecular weight: term used to describe the masses of molecular compounds ---- MW of H2O = 2 (atomic weight of H) + (atomic weight of O) ---- 2(1.01) + (16.0) = 18.02
Acid-Base Behavior and Chemical Structure
• The more polar the H-X bond and/or the weaker the H-X bond, the more acidic the compound • So acidity increases from left to right across a row and from top to bottom down a group
molecule shapes
• The shape of a molecule plays an important role in its reactivity • Lewis Structures do not show the 3-dimensional shape of molecules. For that we need additional theories ------VSEPR: Valence Shell Electron Pair Repulsion Theory ------ Hybrid Orbital Theory ------ Molecular Orbital Theory • Overall shapes of molecules are determined by bond angles and bond lengths • All molecules of the type ABn have a 3-d structure based on one of 5 shapes
What is Stoichiometry?
• The study of mass relationships in chemical reactions ---- Atomic masses ---- Chemical formulas ----- Law of conservation of mass • Chemical reactions are represented by chemical equations ---- Example: the chemical reaction of methane gas and oxygen in the air to produce heat, water vapor and carbon dioxide
Charles's Law
• The volume of a fixed amount of gas at constant pressure is directly proportional to its absolute temperature • A plot of V versus T will be a straight line ex: (V/T)=k
Boyle's Law
• The volume of a fixed quantity of gas at constant temperature is inversely proportional to the pressure • Thus, a plot of V versus P results in a curve since PV=k V=k(1/P)
Avogadro's Law
• The volume of a gas at constant temperature and pressure is directly proportional to the number of moles of the gas • Mathematically, this means V= k ∙ n
polar covalent bonds
• Though atoms often form compounds by sharing electrons, the electrons are not always shared equally • Fluorine pulls harder on the electrons it shares with hydrogen than hydrogen does • Therefore, the fluorine end of the molecule has more electron density than the hydrogen end • This results in a polar covalent bond, or a dipole. H - F 4.0 - 2.1 = 1.9 H get partial positive F gets partial neg
trigonal planer
• Trigonal Planar: 3 electron domains around a central atom - Trigonal Planar if all 3 electron domains are bonding domains - Bent if one of those domains is a nonbonding pair 120 degree angle
Structure and Properties of Alcohols
•Alcohols contain a hydroxyl (OH) group. •Alcohols are classified by the number of C atoms bonded to the C with the OH group. -A primary (1o) alcohol has an OH group on a C bonded only to 1 C atom - A secondary (2o) alcohol has an OH group on a C bonded only to 2 C atoms. -A tertiary (3o) alcohol has an OH group on a C bonded only to 3 C atoms •An alcohol contains an O atom with a bent shape like H2O, with a bond angle of 109.5o. •Alcohols have two polar bonds, C—O and O—H, with a bent shape, therefore it has a net dipole. •Alcohols have an H atom bonded to an O atom, making them capable of intermolecular hydrogen bonding. •All of these properties give alcohols much stronger intermolecular forces than alkanes and alkenes. •Alcohols are soluble in organic solvents. •Low molecular weight alcohols (6 C's or less) are soluble in water. •Higher molecular weight alcohols (6 C's or more) are not soluble in water.
physical properties
•Alkanes contain only nonpolar C-C and C-H bonds. •Alkanes exhibit only weak intermolecular forces, so they have low melting points and boiling points. •Smaller alkanes are gases at room temperature, whereas larger alkanes are liquids. •Alkanes are insoluble in water •Alkanes are less dense than water, meaning that they will float on the surface of water. •As the number of carbons in an alkane increases, the boiling point increases: butane to pentane to hexane increase surface area increasing boiling point
12.8 Focus on the Environment Combustion
•Alkanes have no functional group, so they undergo few reactions. •Combustion is the only reaction of alkanes in this chapter; It is an oxidation-reduction reaction. •In the combustion reaction, alkanes burn in the presence of O2 gas to form CO2 and H2O. •The products, CO2 + H2O, are the same, regardless of the identity of the alkane that undergoes combustion. •If there is not enough O2 to react, incomplete combustion may occur, and carbon monoxide (CO) is formed instead of carbon dioxide (CO2 ). •Carbon monoxide is a poisonous gas that binds to hemoglobin in blood, thereby reducing the amount of O2 that can be transported to cells.
Alkyl Halides
•Alkyl halides contain a halogen atom X (where X = F, Cl, Br, I). •They are classified by the number of C atoms bonded to the C with the halogen. A primary (1 o) alkyl halide has an X group on a C bonded only to 1 C atom A secondary (2 o) alkyl halide has an X group on a C bonded only to 2 C atoms. A tertiary (3 o) alkyl halide has an X group on a C bonded only to 3 C atoms
Alkyl Halides Physical Properties
•Alkyl halides contain a polar C—X bond, thus they contain a net dipole. •They are not capable of intermolecular hydrogen bonding. •As a result, they have higher melting and boiling points than similar alkanes, but lower than alcohols. The boiling and melting points of an alkyl halide will increase with: •the size of the alkyl group •the size of the halogen All alkyl halides are insoluble in water.
Amines: Structure and Bonding
•Amines are organic nitrogen compounds, which are classified by the number of alkyl groups bonded to the N atom. •A primary (1 o) amine has 1 C—N bond, and has the general structure RNH2 . •A secondary (2 o) amine has 2 C—N bonds, and has the general structure R2NH. •Amines are organic nitrogen compounds, which are classified by the number of alkyl groups bonded to the N atom.
Aromatic Compounds
•Aromatic compounds are compounds that contain a benzene ring. •Each C is trigonal planar (i.e., 120° bond angles), making benzene a planar molecule. •Each of these representations has the same arrangement of atoms, but different locations of electrons. •These are resonance structures, and neither is the true structure of benzene. •The actual structure is a combination of both resonance structures, called a hybrid. In this hybrid structure, all three electron pairs in the double bonds are delocalized in the sixmembered ring. •This can be drawn as a circle inside the hexagon.
Focus on Health & Medicine
•Aspirin (acetylsalicylic acid) is similar in structure to natural products. - in the stomach aspirin exists as a neutral organic compound - in the intestines, aspirin exist as an ionic compound
Focus on Health and Medicine Margarine or Butter?
•Butter is made up of saturated fatty acid chains. •A diet rich in saturated fatty acids is widely considered to be unhealthy. •Scientists have attempted to produce alternative versions of butter (margarine) with similar taste and properties, but with some C═C double bonds (i.e., unsaturated fatty acid chains). •Most naturally occurring unsaturated fatty acid compounds are liquids at room temperature. •To make the desired butter alternative, we need a compound that is a solid at room temperature. •This is done by partially hydrogenating unsaturated fatty acid compounds. •This process allows only a few C═C double bonds to remain on the chain, making a solid fatty acid that is not naturally occurring. •Unfortunately, some partial hydrogenations leave trans double bonds on the fatty acid chain. •Trans fatty acids are very similar in shape to saturated fatty acids. •Trans fatty acids are widely considered to be just as unhealthy as saturated fatty acids. •Nutritionists agree that a healthy diet consists of very few saturated or trans fats.
Alkane Nomenclature A. Naming Substituents
•Carbon substituents are called alkyl groups. •An alkyl group is formed by removing 1 H from an alkane. •To name an alkyl group, change the "-ane " ending of the parent alkane to "-yl." •Each alkyl group has a bond that can then be attached to something else.
Functional Groups C. Compounds Containing a C=O Group
•Carbonyl groups (carbon-oxygen double bonds) are present in several different compounds •An aldehyde contains a hydrogen atom directly bonded to the carbonyl carbon. •A carboxylic acid contains an OH group directly bonded to the carbonyl carbon. •An ester contains an OR group directly bonded to the carbonyl carbon.
Carboxylic Acids, Esters, and Amides: Physical Properties
•Carboxylic acids, esters, and amides are all polar compounds. •Only carboxylic acids and 1 o and 2o amides can undergo intermolecular hydrogen bonding. Carboxylic acids have higher boiling points than similar alcohols because there are more hydrogen bonding interactions possible than alcohols. Carboxylic acids also have higher boiling points than esters because esters are incapable of intermolecular hydrogen bonding. 1 o and 2o amides have higher boiling points than 3 o amides and esters because of intermolecular hydrogen bonding.
The Acidity of Carboxylic Acids How Does Soap Clean Away Dirt?
•Soap has been used by humankind for ~2000 years. •Soaps are salts of carboxylic acids that have many C atoms in long hydrocarbon chain. •A soap molecule has two parts: 1. The polar head is the ionic end. 2. The nonpolar tail is the carbon chain of nonpolar C—C and C—H bonds •In water, soap forms micelles, spherical droplets with the ionic heads on the surface and the nonpolar tails packed together in the interior. •Nonpolar hydrocarbon tails trap nonpolar material like grease and oil. •The polar head remains on the surface, sealing off the grease and oil, and washing away in the presence of water
Focus on Health and Medicine Aromatic Drugs, Sunscreens, and Carcinogens
•Some common drugs that contain benzene rings are: acetaminopen and lidocaine and loratadine •A common sunscreen used contains benzene: - p-amineobenzioc acid (PABA) •A common environmental pollutant that is a potential carcinogen has several benzene rings: benzo[a]pyrene
Focus on Health and Medicine Oral Contraceptives
•Synthetic birth control pills are similar in structure to the female sex hormones estradiol and progesterone, but they also contain a C-C triple bond. •The two most commonly used birth control drugs are ethynylestradiol and norethindrone: have alkine and alkene and ketone and alcohol and benzene
Focus on Health & Medicine Penicillin
•The antibiotic properties of penicillin were first discovered in 1928 by Sir Alexander Fleming. •Penicillin interferes with the enzyme that synthesizes bacterial cell walls, killing the bacterium. •All penicillins contain a β-lactam:
Carbonyl Containing Compounds: Structure and Bonding
•The carbonyl carbon atom is trigonal planar, with bond angles of 120o. •O is more electronegative than C, so the carbonyl group is polar. •The carbonyl O is e− rich (δ− ) and the carbonyl C is e− poor (δ+ ). Abbreviations for aldehydes: - CH3CHO - CH3COCH3 or (CH3)2 CO •Abbreviations for ketones: CH3CHO - CH3COCH3 or (CH3)2 CO
Carbonyl Containing Compounds The Chemistry of Vision
•The human eye consists of two types of light sensitive cells—the rod and the cone cells. •The chemistry of vision in the rod cells centers around the aldehyde 11-cis-retinal. •The cis double bond is isomerized into the more stable trans double bond when light hits the retina. •This process sends a nerve impulse to the brain, which is then converted into a visual image. •In order for the process to continue, the all-transretinal must be converted back to 11-cis-retinal. •This is done by a series of biological oxidation and reduction reactions. •The all-trans-retinal aldehyde is first reduced by NADH to an all-trans-retinol alcohol, Vitamin A. •The all-trans-retinol is then isomerized to 11-cisretinol and finally oxidized by NAD+ back to the aldehyde 11-cis-retinal. •As this reaction helps us see in dim light, a lack of Vitamin A in the diet causes night blindness.
Synthetic Polymers Polyesters
•The most common polyester is polyethylene terephthalate (PET) used for materials Dacron and Mylar and in making plastic soft drink bottles. •PET is easily and cheaply made and forms strong stable materials.
Properties of Organic Compounds Solubility
•The rule of solubility is "like dissolves like." •Most organic compounds are soluble in organic solvents. •Hydrocarbons and other nonpolar organic compounds are insoluble in water. •Polar organic compounds are water soluble only if they are small and contain a N or O atom that can hydrogen bond with water.
Cis-Trans Isomers A. Stereoisomers—A New Class of Isomer
•There is restricted rotation around the C atoms of a double bond CH3CH=CHCH3 2-butene •Therefore, 2-butene has two possible arrangements: 1. two CH3 groups on the same side cis isomer 2. two CH3 groups on opposite sides trans isomer •Whenever the two groups on each end of a C═C are different from each other, two isomers are possible. •When the two groups on one end of the double bond are identical (e.g., both H or both CH3 ), no cis and trans isomers are possible. •Stereoisomers are isomers that differ only in the 3-D arrangement of atoms. •Constitutional isomers differ in the way the atoms are bonded to each other
Organic Compounds that Contain Sulfur
•Thiols contain a SH (sulfhydryl) group. •Because S is just below O on the periodic table, thiols are similar to alcohols. •Thiols have a bent shape around the S atom. •However, thiols contain no O—H bonds, so they are incapable of intermolecular hydrogen bonding. •This gives thiols lower boiling and melting points than similar alcohols. ex: CH3CH2—SH ethanethiol •Thiols have a characteristic foul odor (skunk, onions, etc.) •They can be oxidized to disulfides. •The disulfides can be converted back to thiols with a reducing agent, [H], through a reduction reaction. - To make straight hair curly, the disulfide bonds holding the hair proteins together are reduced. •The hair is then turned around curlers, and an oxidizing agent is applied. •This re-forms the disulfide bonds in the hair, now giving it a curly appearance.
Interesting Carboxylic Acids Focus on Health & Medicine
•Three common pain relievers that are also antiinflammatory agents contain a carboxyl group: aspirin ibuprofen naproxen •Pain relievers work because they block the synthesis of prostaglandins, compounds responsible for pain responses in the body.
Hydrolysis of Esters and Amides Focus on Health & Medicine
•Triacylglycerols, common naturally occurring esters, contain three ester groups, each with a long C chain. •They are lipids, water insoluble organic compounds, present in fats and oils •Animals store energy in the form of triacylglycerols. •Using enzymes called lipases, the three ester bonds are hydrolyzed when the triacylglycerol is metabolized. •Diets high in fat lead to obesity, so the "fake fat" olestra (Olean) was invented to replace some triacylglycerols in snack foods. •The lipase enzymes cannot hydrolyze the olestra, so it passes through the body unmetabolized, providing no calories to the consumer.
B. Vitamin C
•Vitamin C—ascorbic acid—is important in the formation of collagen, the connective tissue of the skin. •A deficiency in vitamin C causes scurvy, a condition of sailors in the 1600s who had no access to fresh fruit while at sea. •It has many polar bonds and many O atoms, making it a water-soluble vitamin. vitamin c and other water-soluble vitamins are double in the gastric juices of the stomach and the blood. these vitamins are readily excreted in urine.