ACS Chemistry Final Exam
the number of protons in a neutral atom will equal the
# of electrons
What is ∆G when +∆H and -∆S and will the reaction occur?
+∆G rxn will never occur
1 L
= 1 dm^3 1000 mL
an analytical technique to determine the concentration of a solute.
Titration
What type of compound is expected to have the largest dipole movement?
a bent compound
The _____ is titrated with the ______
titrand titrant
atomic number =
# of protons
mass number =
# of protons + neutrons
How do you calculate formal charge?
(#of valence electrons) - (nonbonding electrons) - (bonding electrons / 2)
What is the equation for dilution
(moles solute before dilution) = (moles solute after dilution) C1V1 = C2V2
What is ∆G when +∆H and +∆S and will the reaction occur?
+∆G at low temperatures -∆G at high temperatures rxn will occur at high temperatures
What are the Hess Law rules
- If you reverse the direction of a reaction then reverse the sign of ΔH. - If you change the stoichiometry of a reaction (by multiplying all stoichiometric coefficients by some constant value), then multiple ΔH by this same value. - When summing thermochemical equations, species in the reactants and products only cancel out if they are the exact same chemical as the exact same phase of matter.
What is ∆G when -∆H and +∆S and will the reaction occur?
-∆G rxn will occur at any temperature
What is ∆G when -∆H and -∆S and will the reaction occur?
-∆G at low temperatures +∆G at high temperatures wil occur at low temperatures
What does R equal when dealing with Liters atm/ mol K
.082
Classify the following as an element, compound, or mixture. If it is a mixture, decide if it is a homogeneous or heterogeneous mixture. 1 Sugar 2 Spaghetti Sauce 3 Phosphorus
1 compound, not a mixture 2 mixture, heterogenous 3 element
a double bond is made up of
1 sigma 1 pie
An ionic bond is stronger (i.e. the lattice energy is more negative) if:
1) The charge on the individual ions is greater 2) The distance between + and - charge is less (smaller ions)
Assigning Oxidation Numbers Rules (3)
1. all elements in elemental form have an oxidation # of zero 2. For a monotonic ion the oxidation number equals the charge on the ion 3. The sum of the oxidation numbers in a molecule will equal the charge on the molecule
How many calories are in 1 kcal
1000 cal
1 atm = ? kPA?
101.325
Give the ground-state electron configuration of an atom in the second period
1s2 2s1
how many valence electrons does hydrogen have?
2
Lone PAIRS of electrons, lone electrons. know the difference
2 e = 1 pair 2 e = 2 e
a triple bond is made up of
2 pi bonds 1 sigma bond
What makes up an alpha particle?
2 protons and 2 neutrons
α-particles β-particles γ-rays
2+ elementary charge 1- elementary charge uncharged
What is the molar volume of a gas?
22.4 L
How many Joules in 1 calorie
4.184
If a 17.0g of impure Ni+ metal reacts with excess carbon monoxide, CO, forming 6.25 L of Ni(CO)4 gas under standard temperature and pressure conditions, what is the percent by mass of Ni+ in impure nickel metal sample? What do you start the stoich equation?
6.25 L Ni(CO)4
What does R equal when dealing with Liters kPA/mol K (L/mol K)
8.3145
What does R equal when dealing with meters/mol K (m^3/mol)
8.3145
heat + C + CO2 ->equil-> 2CO if pressure is increased but temperature is kept constant, what will be the result?
CO will decrease C and CO2 will increase
Solubility of CO 3-
Carbonate is insoluble EXCEPT with NH4+ and alkali metals (Ammonium, and Group 1 metals)
Which element is represented by X
Chromium
Has two ionizable protons (H2SO4)
Diprotic acid
Define Bond Polarity
Electrons will spend most of their time around the most electronegative atom
What is the equation for Pressure?
Force/Area
Acids increase the concentration of what? Bases increase the concentration of what?
H+ OH-
List the 7 strong acids
HCl - hydrochloric acid HBr - hydrogen bromide HI - hydrogen iodide HClO3 - Chloric acid HClO4 - Perchloric acid HNO3 - Nitric acid H2SO4 - Sulfuric acid
Define Isoelectronic
Having the same amount of electrons
if a reaction is carried out in a series of steps, ΔH for the reaction equals the sum of enthalpy changes for the individual steps.
Hess's Law
Electrons configuration rule that states electrons do not pair until they have to. (put one electrons in each electron domain then pair up)
Hund's rule
Solubility of OH- and O2-
Hydroxide and Peroxide are insoluble except with alkali metals, Ca2+, Sr2+, Ba2+
An atom has a valence shell configuration of 1s1. To which group of elements on the periodic table does it belong?
IA alkali metals
What does it mean when an element has a high electron affinity
It means that it can easily accept electrons to form negative ions
What does it mean when an element has a low ionization energy?
It means that it can easily lose electrons
the energy released when one mole of an ionic solid is formed from gaseous ions. Measures the strength of an ionic bond
Lattice energy
Solubility: C2H3O2
Methyl carbonate is soluble
Temperature in Gas Law equations must be in what type of measurement? What is the conversion?
Must be in Kelvin 273.15 + C = K
What is one weak base you should memorize
NH3 (ammonia)
Solubility: NO3-
Nitrate is soluble
List the shape, electron domain geometry, and predicted bond angle of a molecule with 6 electron domains
Octahedral 90º
List one weakness of the Bohr model
Only orbits of specific radii are permitted for the electron in a hydrogen atom.
Assigning Oxidation Number Rule Exceptions
Oxygen = -2 except in Peroxide = -1 Hydrogen = +1 when with nonmetal -1 when with metal Halogens are -1 except when with Oxygen while Fluorine is ALWAYS -2
Gas Law: Pressure- Temperature relationship, at constant volume. Gay-Lusaacs' Law
P/T = constant
P1V1 will always equal________ if temperature and particle numbers are constant
P2V2
Gas Law: Pressure-Volume relationship, at constant temperature. Boyle's Law
PV = constant
What is the main gas law equation?
PV=nRT (pressure x volume) =
An experimental phenomena associated with atoms having unpaired electrons - which states such substances are attracted to magnetic fields
Paramagnetism
Solubility of PO4 3-
Phosphate is insoluble EXCEPT with NH4+ and alkali metals (Ammonium, and Group 1 metals)
Can be observed without changing the identity & composition of a substance
Physical property (color, density, melting point) all intensive. do not depend on amount of substance e
Describe the atom. What makes up the nucleus and where do electrons reside
Protons and neutrons form the small, dense nucleus; electrons are found in a diffuse cloud around the nucleus; most of the volume of an atom is empty space.
Phrase to remember greatest wavelength/least frequency to smallest wavelength/greatest frequency
Rain Makes Igloos Very Unstable - Xtra Gay radio - microwave - infared - visible - UV - xray - gamma
Who discovered the nucleus by observing the scattering of α-particles off of a thin gold foil & discovered the proton by bombarding N2 with α-particles.
Rutherford
Who discovered the proton?
Rutherford by bombarding N2 with alpha particles
Solubility of Cl- Br- I-
Soluble except in Ag2+, Pb2+, Hg2+
6 electron domains results in what type of hybridization?
Sp3d2
Solubility of SO4 2-
Sulfate is soluble except in Sr2+, Hg2+, Ba2+, Pb2+, Ca2+
Solubility of SO3 2-
Sulfite is insoluble EXCEPT with NH4+ and alkali metals (Ammonium, and Group 1 metals)
Solubility of S 2-
Sulfur is insoluble EXCEPT with NH4+, alkali metals, (Ammonium, Group 1)
Consider this equation at constant temperature and volume 2SO2 (g) + O2 (g) ->equilibrium-> 2SO3 (g) What is the effect of removing some SO3 from a system initially at equilibrium
The concentration of SO2 decreases more than O2
Why are lattice energies listed as positive values instead of negative values?
This represents the energy needed to break apart one mole of substance, rather than the energy released when the substance forms.
Gas Law: Temperature-Volume relationship, at constant pressure. What is the constant for Charle's Law?
V/T = constant
Energy is released when
a bond forms
What does a bonding electron domain represent?
a bond. single or multiple
What does a nonbonding electron domain represent?
a lone PAIR of electrons
What particle, if lost from the nucleus, would NOT cause a change in the atomic number?
a neutron because it has no charge
What do neutralization reactions take place in
acid + base leaving salt + water
two or more different physical forms in which an element can exist. Graphite, charcoal, and diamond are all ________ of carbon.
allotropes
a substance that produces ions when dissolved in solution.
an electrolyte
Identify the bond that would form between an element with a low ionization energy and an element with a high electron affinity
an ionic bond
When resonance structures are shown, the real structure is actually an
average of all of them
when an atom of an electropositive atom becomes an ion it..?
becomes larger
Energy is required to
break a bond
How did Thompson discover the Electron?
by cathode
Which are larger - cations or anions
cations (+)
Cannot be observed without changing the identity & composition of a substance
chemical property
The type of bond that results when both elements contribute electrons but one element furnishes both electrons
coordinate covalent bond
The type of bond that results when both elements contribute electrons to form a shared pair
covalent bonds
a molecule in which a concentration of positive electric charge is separated from a concentration of negative charge.
dipole
High energy photons have enough energy to do what?
disrupt covalent bonds
A solution will conduct electricity if it contains what?
dissolved ions
List the electron domain geometry & molecular geometry of a molecule with 2 electron domains (2 bonding 0 nonbonding)
electron domain geometry: linear molecular geometry: linear
List the electron domain geometry & molecular geometry of a molecule with 6 electron domains (6 bonding 0 nonbonding)
electron domain geometry: octahedral molecular geometry: octahedral ex: SF6
List the electron domain geometry & molecular geometry of a molecule with 6 electron domains (5 bonding 1 nonbonding)
electron domain geometry: octahedral molecular geometry: square pyramidal ex: BrF5
List the electron domain geometry & molecular geometry of a molecule with 4 electron domains (2 bonding 2 nonbonding)
electron domain geometry: tetrahedral molecular geometry: bent/nonlinear ex: H2O
List the electron domain geometry & molecular geometry of a molecule with 4 electron domains (4 bonding 0 nonbonding)
electron domain geometry: tetrahedral molecular geometry: tetrahedral
List the electron domain geometry & molecular geometry of a molecule with 4 electron domains (3 bonding 1 nonbonding)
electron domain geometry: tetrahedral molecular geometry: trigonal pyramidal ex: NH3
List the electron domain geometry & molecular geometry of a molecule with 5 electron domains (2 bonding 3 nonbonding)
electron domain geometry: trigonal bipyramidal molecular geometry: linear ex: I3-
List the electron domain geometry & molecular geometry of a molecule with 5 electron domains (4 bonding 1 nonbonding)
electron domain geometry: trigonal bipyramidal molecular geometry: see saw shape ex: SF4
List the electron domain geometry & molecular geometry of a molecule with 5 electron domains (3 bonding 2 nonbonding)
electron domain geometry: trigonal bipyramidal molecular geometry: t-shaped ex: CIF3
List the electron domain geometry & molecular geometry of a molecule with 5 electron domains (5 bonding 0 nonbonding)
electron domain geometry: trigonal bipyramidal molecular geometry: trigonal bipyramidal ex: PCl5
List the electron domain geometry & molecular geometry of a molecule with 3 electron domains (2 bonding 1nonbonding)
electron domain geometry: trigonal planar molecular geometry: bent
List the electron domain geometry & molecular geometry of a molecule with 3 electron domains (3 bonding 0 nonbonding)
electron domain geometry: trigonal planar molecular geometry: trigonal planar
Electronegativity periodic trend
electronegativity is greater the higher up on the right of the periodic table
δ+ goes over the ____________ and δ- over the ___________ atom
electropositive, electronegative
Properties that do depend on the amount of matter present.
extensive
What does the Oxidizing Agent do in a redox reaction? (aka the oxidant)
gains an electron. Becomes reduced
What does the Reducing Agent do in a redox reaction? (aka the Reductant)
gives away an electron. Becomes oxidized
What does a low vapor pressure value indicate (little tendency to change from liquid to gas)
higher heat of vaporization higher boiling points high surface tension
What is effective nuclear charge and what is its periodic trend
how tightly electrons are held greatest in bottom right.
The boiling point of H2O, compared with other members of the series can be explained by
hydrogen bonding
heat + CaSO3 ->equal-> CaO + SO2 what will cause an increase in pressure when equilibrium is reestablished?
increasing the reaction temperature
Nearly all the mass in an atom is located _________ because both ______ & ______ are located there, and each of these particles have a mass larger than the ______
inside the nucleus protons & neutrons electron
an electronegativity difference ≥ 1.7 indicates an ________ (sometimes you see 2.0 instead of 1.7). An electronegativity difference ≤ 0.5 is generally considered ___________. If it is somewhere in the middle it is considered ________
ionic nonpolar polar
What type of bond has a low conductivity as a solid but a high conductivity when fused?
ionic Ex: NaCl
Bond formed from: metal+nonmetals
ionic bond
Which type of compound has a higher melting point?
ionic compounds have higher melting points that molecular compounds
two or more compounds with the same formula but a different arrangement of atoms in the molecule and different properties
isomer
Forms of the same elements that differ in amount of neutrons
isotopes
What has to be true of a non polar molecule that has polar bonds
it must be symmetric enough so that all the dipoles cancel out
Atomic/ionic radii periodic trend
largest is on the bottom left
List the shape, electron domain geometry, and predicted bond angle of a molecule with 2 electron domains
linear 180º
What does a high vapor pressure value indicate
lower heats of vaporization lower boiling points less surface tension
measure of how much matter an object contains
mass
how to find the correct number of neutrons
mass number - atomic number
What type of element tends to lose electrons
metals
How do you calculate Molarity
mol/L
bond formed from: two nonmetals
molecular compound
What do the 4 quantum numbers stand for?
n = energy level l = (n-1) ml -l to l mn 1/2 or -1/2 (spin)
Which drop in energy level results in the greatest emission of energy?
n=2 to n=1
poor conductors, brittle
nonmetal
What type of element tends to gain electrons
nonmetals
What does an element need to have to be paramagnetic
one or more unpaired electrons
What are rows What are columns
periods are rows groups of columns
What two subatomic particles have the most mass, but occupy very little of the volume of an atom
protons and neutrons
reaction in which electrons are transferred from one reactant to the other
redox reactions
List the quantum numbers for the s, p, d, and f orbitals
s 1,0,0 p 2, 1, -1-0-1 d 3, 2, -2--1-0-1-2 f 4, 3 -3--2--1-0-1-2-3
Define electropositive atoms. Where are they located
smallest value, least electronegative. Located bottom left of periodic table
The strong bases are what?
soluble group 1 group 2 metal hydroxides
The ______ is dissolved in the _______
solute solvent
2 electron domains results in what type of hybridization?
sp
Thompson discovered the Plum Pudding Model - what was that? Who proved him wrong?
stated that nucleus was a scattered positive sphere with electrons embedded in it, was proved wrong by Rutherford who did the gold foil experiment
What does a neutralization reaction occur between? What does it result in?
strong acid + base H2O
contains more dissolved solute than a saturated solution at that temperature.
supersaturated solution
What effects the vapor pressure of a liquid
temperature
List the shape, electron domain geometry, and predicted bond angle of a molecule with 4 electron domains
tetrahedral 109.5º
When alpha particles were shot at a metal foil target, most passed through without deflections, while others deflected at large angles. What did this suggest to Rutherford?
that the atoms of the metal were mostly empty space, while the nucleus consisted of most of the mass which included highly condensed positive particles (which caused the deflection).
What isIonization energy, and what is its periodic trend
the amount of energy required to remove an electron from ground state largest amount energy is top right
The greater the wavelength of a photon..?
the lower its frequency
What did Millikan discover from his oil drop experiments?
the magnitude of the charge on an electron
What is Electron affinity, and what is its periodic trend
the potential energy change when and electron is added to a gaseous atom or ion the more negative, the more energy released most negative at top right
PCl5 ->equilibrium-> PCl3 + Cl2 what will cause an equilibrium shift to the right
the removal of Cl2
equal volumes of gas under the same temperature and pressure will have...?
the same amount of molecules (avagondros)
The greater the frequency of a photon...?
the shorter its wavelength
How does a sodium ion differ from a sodium atom?
the sodium ion has fewer electrons
What is the molecular weight?
the sum of the mass of each element
the numerical value of the equilibrium constant for any chemical change is effected by changing the what
the temperature
List the shape, electron domain geometry, and predicted bond angle of a molecule with 5 electron domains
trigonal bipyramidal, 120º equitorial & 90º axial
List the shape, electron domain geometry, and predicted bond angle of a molecule with 3 electron domains
trigonal planar 120º
contains less dissolved solute than a saturated solution at that temperature
unsaturated solution
measure force of gravity of an object
weight
What is the formula for ∆G?
∆G = ∆H-T∆S