JMU Chem 120 Final

Conjugate Acid-Base Pairs

Conjugate base: the base that remains after an acid gives up a proton Conjugate acid: the acid that is formed when a base accepts a proton

DNA n RNA

DNA: A-T C-G RNA: A-U C-G

How to find H₃O⁺ from pH

H₃O⁺= 10⁻pH pH= 8.34 10^(-8.34) H₃O⁺= 5.0 x 10⁻⁹

composition of ion

cation= positively charged ion, more protons than electrons (loss of electrons) anion= negatively charged ion, more electrons than electrons (gain of electrons)

chemical change

conversion of a substance into different substance (ex: rusting iron)

density

d = m/v

nuclear equation

equation showing the change from the initial nucleus(reactant) to the final nucleus 238/92U→234/90Th + 4/2He

properties of elements

only one type of material made up of atoms

How to find pOH from OH⁻

pOH= -log[OH⁻] OH⁻= 4.82 x 10⁻⁵ pOH= -log[4.82 x 10⁻⁵] pOH= 4.32

Amphoteric

substance that can act as both an acid and a base

temperature

water boils at = 212°F, 100°C, and 373K water freezes at = 32°F, 0°C, and 273K

La Chatelier's Principle

when a stress is places on a reaction at equilibrium will shift in the direction that will relieve the stress

saponification

heating a fat/oil with strong base to make fatty acid salts (soap)

suspension

heterogenous, non-uniform mixtures in which the particles are so large they can't remain suspended permanently ( and can often be seen by eye)

solutions

homogenous mixture where one substance is uniformly dispersed into another

stoichiometric mixtures

if you have exactly the amounts of reactants to react with nothing leftover, the mixture is called stoichiometric

properties of compound

made of 2 or more elements chemically combined in the same proportion, made up of molecules

properties of a mixture

made of 2 or more substances physically combined ∙heterogenous: contains two or more phases (ex: soda, OJ) ∙homogenous: contains a uniform composition (ex: salt water)

dilution

making a concentrated solution more dilute by adding solvent to it

measured v. exact numbers

measured = obtained through measurement and are uncertain exact = obtained through counting and are certain

intermolecular forces: melting/boiling point

melting: the stronger the interaction, the higher the melting point boiling: the stronger the interaction, the higher the boiling point

colloid

mixture in which the solute particles are larger than the particles in a solution but small enough that they remain suspended in the solvent

molarity

moles of solute / liters of solution

HDL= good cholesterol LDL= bad cholesterol

monounsaturated= lowers LDL, raises HDL polyunsaturated= lowers both saturated= raises both trans= raises LDL, lowers HDL

mass/volume percent

(grams solute / milliliters solution) ∙ 100%

mass percent

(mass solute / mass solution) ∙ 100%

volume percent

(volume solute / volume solution) ∙ 100%

limiting reactant problems

1. convert amount of each reactant to the # of moles of a product 2. whichever reactant produces less of the product is the limiting reactant

intermolecular forces: strongest to weakest

1. ionic bonds 2. covalent bonds 3. hydrogen bonds 4. dipole-dipole attractions 5. dispersion forces

Rules for Oxidation states

1. o# of a free element is always zero (ex: Ca, N₂) 2. o# of a monoatomic ion is always the charge of the ion, in compounds the o# of Group 1+2 metals are always +1 and +2 3. In a compound, the o# of fluorine is always -1 4. o# of oxygen is usually -2 (except peroxides and bound to F) 5. o# of other halogens is often -1 (except when combined with O or F) 6. o# of hydrogen is usually +1 (except when its only bound to a metal ((-1)) ex: BaH₂) 7. all of the o# must add up to zero 8. all of the o# in a polyatomic ion must add up to overall charge of the ion

protein structure

1. primary= basic sequence of amino acids held together by peptide bonds 2. secondary= hydrogen bonds between peptides forming alpha helixes and beta pleated sheets 3. tertiary= compact 3-d shape formed by interactions (h-bonds) between r groups 4. quaternary= interactions between two or more polypeptide subunits

colligative properties: physical property of a substance that depends only on the concentration of solute

1. vapor pressure -how quickly a liquid will evaporate -adding solute decreases vapor pressure 2. boiling point -with a lower vapor pressure, it is harder for a liquid to vaporize -adding solute increases boiling point 3. freezing point -solute particles prevent liquid particles to organize themselves to condense into a solid -adding solute decreases the freezing point

scientific notation

3.94 x 10⁷= 39400000 0.000008 = 8.0 x 10⁻⁶

mole conversions

6.022 x 10²³ of anything

half-life calculations

64 mg of 234Th t1/2 = 24.1 1 half life= 32mg and 24.1 days 2 half lives= 16mg and 48.2 days 3 half lives= 8mg and 72.3 days 4 half lives=4mg and 96.4 days 5 half lives= 2mg and 120.5 days

Bronsted-Lowry

Acid: compound that can donate H+ Base: compound that can accept H+

Cis v trans fatty acids

Cis= larger atoms on a double bond are on the same side of the bond trans= larger atoms on a double bond are on opposite sides

properties of metals

Metals left/below metalloid line= ∙solid at room temp ∙shiny ∙malleable= can be beaten into sheet/foil ∙ductile= can be drawn into wire ∙conduct heat and electricity well ∙most have high densities and high melting points

How to find OH⁻ from pOH

OH⁻=10⁻pOH pOH= 5.70 10^(-5.70) OH⁻= 2.0 x 10⁻⁶

properties of metalloids

On metalloid line= ∙somewhat malleable ∙somewhat shiny ∙semi-conductive ∙intermediate density ∙sometimes considered nonmetals

combined gas law

P₁V₁/T₁ = P₂V₂/T₂

properties of nonmetals

Right/ above metalloid line= ∙relatively low freezing and boiling points ∙relatively low densities ∙brittle ∙dull ∙insulating

specific gravity

SG = density of substance / density of water

How to find pH from H₃O⁺

[HNO₃]=[H₃O⁺]= 0.0018 M pH= -log[H₃O⁺] pH= 2.74

Ion product of water

[H₃O⁺][OH⁻]=Kw

precipitation reactions

a double replacement will usually form one soluble product and one insoluble one

conversion factor

a ratio of equivalent measurements used to convert a quantity from one unit to another

peptides

amide bond that forms between the -COO⁻ group of one amino acid and the -NH₃⁺ group of another

electromagnetic radiation

amplitude= height of wave, determines how bright the light is wavelength= distance between peaks on a wave, related to color frequency= number of waves that pass a point in one second

composition of atom

atomic number= number of protons mass number= number of nucleons, distinguishes isotopes

types of chemical equations

combination: only one product decomposition: only one reactant single replacement: element + ionic compund double replacement: 2 ionic compounds combustion: reaction with O₂ oxidation/reduction: electron transfer

physical change

composition remains the same but state, size, or appearance change (ex: grinding chalk into a powder)

linear electron group geometry

electron groups= 1 bonded atoms= 2 lone pairs= 0 bond angles= 180° molecular shape= linear

trigonal planar electron group geometry small

electron groups= 2 bonded atoms= 2 lone pairs= 1 bond angles= 120° molecular shape= bent

trigonal planar electron group geometry big

electron groups= 3 bonded atoms= 3 lone pairs= 0 bond angles= 120° molecular shape= trigonal planar

tetrahedral electron group geometry middle

electron groups= 4 bonded atoms= 3 lone pairs= 1 bond angles= 109° molecular shape= trigonal pyramid

tetrahedral electron group geometry big

electron groups= 4 bonded atoms= 4 lone pairs= 0 bond angles= 109° molecular shape= tetrahedral

tetrahedral electron group geometry small

electron groups=4 bonded atoms=2 lone pairs= 2 bond angles= 109° molecular shape= bent

precision v. accuracy

precision = close to each other accuracy = close to the actual number

food calories

protein= 4 calories in a gram fat= 9 calories in a gram carb= 4 calories in a gram

specific heat

q= mc∆T q= heat energy m= mass c= specific heat ∆T= change in temperature

empirical formula

simplest positive integer ratio of atoms present in a compound

hypertonic

solution with a higher concentration than a cell -water will flow out of the cell to the surrounding solution

hypotonic

solution with a lower concentration than a cell -water will flow into the cell from the surrounding solution

isotonic

solution with the same osmotic pressure as body fluids

heat of fusion

the amount of heat required to MELT ONE GRAM of a substance (similar to specific heat but no change in temp) Q= m∙Hf

heat of vaporization

the amount of heat required to VAPORIZE ONE GRAM of a substance (no change in temp) Q= m∙Hv

molar mass

the mass of one mole of an element or compound, numerically the same as the atomic mass on the periodic table for an element or sum of atomic masses for compounds

Meaning of Ksp

the more soluble a compound is, the more ions it dissociates into making the Ksp value higher

limiting reactant

the reactant that can produce the least amount of product or limits how much product can be made

excess reactant

the reactant that is leftover after the limiting reactant is used up completely

structural isomers

two or more compounds that have the same locular formula but different arrangements of atoms

covalent bonding

when electrons are shared between two nonmetal atoms

ionic bonding

when electrons are transferred from a metal atom to a nonmetal atom and the positive and negative ions are attracted to each other

nucleotide

∙3 components -pyrimidine or purine base -pentose(5 carbon sugar) -phosphate group

Alpha particle

∙He nucleus ∙2 protons + 2 neutrons ∙mass # of 4, atomic # of 2, charge of 2+ ∙very low penetration ∙a lot of damage to surface cells

factors that affect reaction rate

∙activation energy (higher ae = slower rate) ∙temperature of the reaction (higher temp = faster rate) ∙concentration of the reactants (higher concentration = faster rate) ∙presence of a catalyst (adding catalyst = faster rate) ∙particle size (larger particles = slower reaction)

naming ionic compounds

∙always named cation first, anion second ∙do not specify the number of ions ∙add -ide to the end of theanion ∙(ex: KBr = Potassium bromide)

amino acid properties

∙an ammonium group (-NH₃⁺) ∙a carboxylate group (-COO⁻) ∙essential amino acids cannot be synthesized in the body; they must be consumed

atomic radius

∙as you go down a column the radius INCREASES SIGNIFICANTLY ∙as you go across a row the radius DECREASES SLIGHTLY

lipids

∙biomolecules that are non polar and insoluble in water ∙include: -fats -oils -waxes -steroids

steroids

∙compounds containing the steroid nucleus (four fused carbon rings) ∙do not contain fatty acids

properties of gases

∙compressible ∙low densities ∙always mix completely ∙completely fill container ∙exert pressure in all directions

covalent non-polar bonds

∙evenly shared electrons ∙0.0-0.4 electronegativity ∙symmetrical geometry (NO lone pairs) with the exterior atoms all the SAME

molecular naming

∙greek prefixes before the names indicating the number of atoms ∙second element written with -ide at end ∙mono not used on first element

beta particle

∙high energy electron ∙mass # of 0, atomic # of -1, charge of 1- ∙fairly low penetration ∙moderate damage over a small depth

gamma

∙high-energy radiation ∙mass # of 0, atomic # of 0, charge of 0 ∙complete penetration ∙damage spread out over entire body

Fatty acids

∙long unbranched carbon chain with a carboxylic acid group at one end ∙Saturated fatty acid= chain contains only C-C single bonds ∙unsaturated fatty acid= chain contains one or more C-C double bonds

common disaccharides

∙maltose -glucose+glucose -malt sugar -used in cereals and candy ∙lactose -glucose+galactose -milk sugar -found in milk/dairy products ∙sucrose -glucose+fructose -table sugar -obtained from beets and sugar cane

types of RNA

∙messenger RNA (mRNA): carries genetic info from DNA to the ribosomes ∙transfer RNA (tRNA): brings amino acids to the ribosome to make the protein ∙ribosomal RNA(rRNA): major component of ribosomes

nucleic acid

∙molecules that store information for cellular growth/reproduction ∙ex: DNA and RNA

non electrolyte

∙not conductive ∙when dissolved, it does not ionize at all ∙carbon-based molecular compounds (C₁₂H₂₂O₁₁(sugar), CH₃OH (methanol),CH₄N₂O (urea)

covalent polar bonds

∙partial separation of charge due to unequal sharing of the electrons ∙0.5-1.8 electronegativity ∙symmetrical geometry (NO lone pairs) with DIFFERENT exterior atoms ∙any combination of atoms with a non symmetrical geometry ∙permanent dipole

polysaccharides

∙polymer of many monosaccharides linked together ∙common poly: -amylose -amylopectin -glycogen -cellulose (all 4 made of only glucose)

structure of nucleic acids

∙polymers of nucleotides ∙linked by phosphodiester bonds between sugars in adjacent nucleotides ∙one end of the nucleotide has a free phosphate group, and the other end has a sugar with a free hydroxyl group

positron

∙positively charger electron ∙mass # of 0, atomic # of 1, charge of 1+

Equilibrium constant

∙ratio of concentration of the products to the concentration of the reactants ∙if K value is less than one the reaction will shift left ∙if K value is more than one the reaction will shift right

Ka and Kb

∙the stronger an acid or base, the more ions it forms in water ∙the stronger an acid or base is, the larger its Ka or Kb value is

Dalton's law

∙the total pressure of gas in a system is the sum of the partial pressures of each component gas ∙Ptotal = P₁+P₂+...+P₉

ideal gas law

∙the volume of a gas is related to pressure, temp, and # of moles ∙PV = nRT

Triacylglycerols(fats/oils)

∙triesters of glycerol and three fatty acids

disaccharides

∙two monosaccharides linked together ∙glycosidic bond: ether bond formed when two hydroxyl groups react and H2O is removed

stock method

∙used when transition metals can form more than one cation ∙written with Roman numerals indicating charge ∙Fe₂S₃= iron (III) sulfide

strong electrolyte

∙very conductive ∙when dissolved, it disassociates completely ∙soluble ionic compounds (salts) and bases ∙HCl, Her, HI, HNO₃, HClO₄, H₂SO₄

weak electrolyte

∙weakly conductive ∙when dissolved, it ionizes partially ∙weak acids (HF, HC₂H₃O₂) and bases (NH₃)

Dissolution of compounds

∙when a solute dissolves into the solvent ∙solute-solvent bonds need to be stronger than solute-solute bonds ∙polar dissolve polar, non polar dissolve non polar

Reduced

∙when an element gains electrons (becomes negative) ∙oxidizing agent/ oxidant

Oxidized

∙when an element loses electrons (becomes positive) ∙reducing agent/ reductant

biological effects of radiation

∙when radiation hits molecules, electrons are knocked loose "ionizing radiation" ∙ions are extremely reactive and cause damage to living cells ∙cancer cells are extra reactive to radiation ∙radiation can also cause cancer, tumors, anemia, and mutations in healthy cells

line angle drawings

∙zig-zag lines representing carbon chains, with branches off of them as needed ∙carbon always makes 4 bonds ∙all other atoms must be written along with any hydrogen atoms attaches directly to those atoms