AP Chemistry Midterm Review

Mercury
Polyatomic Ion
Hg2^+2
Ammonium
Polyatomic Ion
NH4^+1
Nitrite
Polyatomic Ion
NO2^-1
Nitrate
Polyatomic Ion
NO3^-1
Sulfite
Polyatomic Ion
NO3^-1
Sulfate
Polyatomic Ion
SO4^-2
Hydrogen Sulfate
Polyatomic Ion
HSO4^-1
Hydroxide
Polyatomic Ion
OH^-1
Cyanide
Polyatomic Ion
CN^-1
Phosphate
Polyatomic Ion
PO4^-3
Hydrogen Phosphate
Polyatomic Ion
PO4^-3
Dihydrogen Phosphate
Polyatomic Ion
H2PO4^-1
Thiocyanate
Polyatomic Ion
NCS^-1
Carbonate
Polyatomic Ion
CO3^-2
Hydrogen Carbonate
Polyatomic Ion
HCO3^-1
Hypochlorite
Polyatomic Ion
ClO^-1
Chlorite
Polyatomic Ion
ClO2^-1
Chlorate
Polyatomic Ion
ClO3^-1
Perchlorate
Polyatomic Ion
ClO4^-1
Acetate
Polyatomic Ion
C2H3O2^-1
Permanganate
Polyatomic Ion
MnO4^-1
Dechromate
Polyatomic Ion
Cr2O7^-2
Chromate
Polyatomic Ion
CrO4^-2
Peroxide
Polyatomic Ion
O2^-2
Oxalate
Polyatomic Ion
C2O^-2
mega
M
10^6
kilo
k
10^3
deka
da
10^1
deci
d
10^-1
centi
c
10^-2
milli
m
10^-3
micro
µ
10^-6
nano
n
10^-9
hydrochloric acid
Strong Acid
HCl
hydrobromic acid
Strong Acid
HBr
hydroiodic acid
Strong Acid
HBr
perchloric acid
Strong Acid
HClO4
nitric acid
Strong Acid
HNO3
periodic acid
Strong Acid
HIO4
sulfuric acid
Strong Acid
H2SO4
chloric acid
Strong Acid
HClO3
Synthesis Reaction
Reaction involves ELEMENTS combining to form a SINGLE substance

e.g.: A solid piece of sodium is dropped into a container of fluorine gas 2Na + F2 → 2NaF

Decomposition Reaction
Reaction involves only ONE REACTANT, products are SIMPLE SALTS and OXIDE GASES…..CARBONATE = CO2 + other……HYDROXIDE = H2O + other

Memorize: 2H2O2 → 2H2O + O2 (hydrogen peroxide)….and… 2KClO3 → 2KCl + 3O2 (potassium chlorate)

e.g.: Solid calcium carbonate is heated
CaCO3 → CO2 + CaO

Combustion Reaction
Reaction when a substance COMBINES with OXYGEN (O2)…..HYDROCARBON = H2O + CO2…..NON-HYDROCARBON = combine oxygen with non-hydrocarbon

e.g.: Octane (C8H18) is burned
2C8H18 + 25O2 → 16CO2 + 18H2O

Mixing Two Salt Solutions Reaction
KNOW SOLUBILITY RULES…..write the net ionic equation and be able to identify spectator ions

e.g.: A solution of iron III sulfate is added to a solution of tin II chloride Sn^+2 + 2Fe^+3 → Sn^+4 + 2Fe^+2

Simple Redox Reaction
Oxidized, reducing agent = lose electron
Reduced, oxidizing agent = gain electron

e.g.: A piece of zinc is oxidized by placing it into a solution of aluminum nitrate
3Zn + 2Al^+3 → 3Zn^+2 + 2Al

Complex Redox Reaction
Use the “Common Oxidation State Changes” page to predict products and HALF-REACTION METHOD to solve it in both an acid and base environment to balance the reaction

e.g.: A solution of tin II chloride is added to an acidified solution of potassium permanganate
5Sn^+2 + 2MnO4^- + 16H^+ → 5Sn^+4 + 2Mn^+2 + 8H2O

Hydrolysis Pure Alkali Metal Reaction
2X + 2H2O → 2X^+2 + 2OH^- + H2
Hydrolysis Alkali Earth Metal Reaction
X + 2H2O → X(OH)2 + H2
Hydrolysis Alkali Metal Hydride Reaction
XH + H2O → X^+ + OH^- + H2
Hydrolysis Alkali Earth Metal Hydride Reaction
XH2 + 2H2O → X(OH)2 + 2H2
Hydrolysis Alkali Metal Oxide Reaction
X2O + H2O → 2X^+ + 2OH^-
Hydrolysis Alkali Earth Metal Oxide Reaction
XO + H2O → X(OH)2
Hydrolysis Nonmetallic Oxide Reaction
General Formula = nonmetallic oxide + water → acid
If the acid is a STRONG ACID then a H is removed and it becomes H^+ + (strong acid – a H)^-
Strong Acid and Strong Base Reaction
H^+ + OH^- → H2O

Strong Bases tend to end with HYDROXIDE

Strong Acid and Weak Base Reaction
H^+ + weak base → (weak base + H)^+

Weak Bases tend to end with INE

Weak Acid and Strong Base Reaction
OH^- + strong base → H2O + (strong base)^-

Strong Bases tend to end with HYDROXIDE

Weak Acid and Weak Base Reaction
weak acid + weak base → (weak base)^+ + (weak acid)^-

Weak Bases tend to end with INE

OH^-
Base
pH
H^+
Acid
pH>7
Proton donors
Solubility Rules
(1) All Nitrate (No3-1) salts are soluble
(2) Most salts containing the alkali metal ions (Li+, Na+, K+, Cs+, Rb+) and the ammonium ion (NH4+) are soluble
(3) Most chloride, bromide, and iodide salts are soluble. Notable exceptions are salts containing the ions Ag+, Pb+2, and Hg2+2
(4) Most sulfate salts are soluble. Notable exceptions are BaSO4, PbSO4, Hg2SO4, and CaSO4
(5) Most hydroxide salts are nonsoluble. The important soluble hydroxides are NaOH and KOH. The compounds Ba(OH)2, Sr(OH)2, and Ca(OH)2 are soluble
(6) Most sulfide (S-2), carbonate (Co3-2), chromate (CrO4-2), and phosphate (PO4-3) salts are nonsoluble
Sig Figs
Any non-zero digit is significant
Any zero to the left of non-zero digits is not significant
Any zero between significant digits is significant
Zeroes at the end of the number and to the right of the decimal point are significant
Zeroes at the end of the number without a decimal point are not significant
Density
D=M/V
JJ Thompson
Cathode ray tube
Plum Pudding Model : found that atoms must have negative particles (electrons)
Milikan
Spray oil particles in a chamber
Found the mass of electron
Rutherford
Gold Foil Experiment
Atom is mostly empty, small positive center
Dalton
First person to publish a table of relative atomic masses
Some were were wrong (didn’t know about diatomic elements)
Average atomic mass of an element
(mass of isotope)x(percent present) + (mass of another isotope)x(percent present) = amu
Avogadro’s Number
6.022 x 10^23 = 1 mole
Mass Percent in a Compound
Take the mass of each element and multiply by how many moles of each element is present. Add all the numbers together (A). To find the mass percent, divide the total mass of the element by the total mass of the compound (A) and multiply by 100.
Empirical Formula
A formula showing the lowest whole number ratio of atoms in a compound

Find out how many moles are present for each element and divide it by the element with the smallest moles present to get the empirical formula.

Molecular Formula
A formula that tells how many atoms are present in a molecule

Take the molar mass of the molecular formula and divide it by the molar mass of the empirical formula which will give you a whole number. Times the values in the empirical formula by this whole number to find the molecular formula

“like dissolves like”
Polar dissolves polar
Non~polar dissolves non~polar
Polar dissolves ionic (cause it’s polar)
Water is polar
Molarity
M
moles/L
expression of concentration
Dilution
M1V1=M2V2
Precipitation
Ax+Bz → Az + Bx
cations always go first
know solubility rules
Cation
Positive ion
Anion
Negative ion
Molecular equation
Gives overall reaction, good for stoichiometry
Complete ionic equation
All strong electrolytes are shown as ions
Net ionic equation
Only shows species that go through chemical change
Spectator ions left out
Oxidation States
OIL RIG
(1) An element (by itself) 0
(2) An ion (with the charge) charge of the ion
(3) Fluorine in its compound -1
(4) Oxygen (except: peroxides) -2 (-1)
(5) Hydrogen +1
Kinetic Energy
KE = (1/2)mv^2
Work
measure in joules (J)
Force x Distance (FxD) OR Pressure x Change in Volume (Px∆V)
Energy loss (system expands) Work is negative
Energy gained (system contracts) Work is positive
Exothermic
Heat flows out of the system
Endothermic
Hear flows into system
∆E
q (heat) + w (work)
-∆E system loses NRG
+∆E system gains NRG
∆H/Enthalpy change/”heat of reaction”
q (heat) = mC∆T
endothermic ∆H>0
exothermic ∆H
Heat Equation
q = mC∆T (J)
Wavelength
λ (m)
Speed of light
c = 3.00 x 10^8 m/s
Frequency
ν (s^-1) or (Hz)
∆E per photon
hν (J per photon)
h = 6.626 x 10^-34 Js
Bohr Model
E = -2.178 x 10^-18 J (z^2/n^2)
Heisenberg
Heisenberg Uncertainty Principle
limit how certain we are of position and momentum at the same time, radiation used to find particle changes the particle’s momentum
Aufbau
Aufau Principle
electrons fill in order from lowest to highest energy
Pauli Exclusion Principle: no two electrons in the same atom can have the same four quantum numbers
↓↑ yes ↑↑no ↓↓no
Hund
Hund’s rule
have to fill all the boxes before the second time goes through
↑ ↑ ↑ yes ↑↓↑ no
First ionization energy
↑→
big atom = low IE
small atom = big IE
Atom size
↓←
effective nuclear charge = protons – core e⁻
(2,0)
sp
linear
180°
(3,0)
sp²
trigonal planar
120°
(2,1)
sp²
bent
(4,0)
sp³
tetrahedral
109.5°
(3,1)
sp³
trigonal pyramidal
(2,2)
sp³
bent
(1,3)
sp³
linear/terminal
NA
(5,0)
sp³d
trigonal bipyramidal
90° + 120° + 180°
(4,1)
sp³d
seesaw
90° + 120° + 180°
(3,2)
sp³d
T-shaped
90° + 180°
(2,3)
sp³d
linear
180°
(6,0)
sp³d²
octahedral
90° + 180°
(5,1)
sp³d²
square pyramidal
90°
(4,2)
sp³d²
square planar
90°
Single Bond
Sigma bond (δ)
Double Bond
Sigma bond and Pi bond
Triple Bond
Sigma bond and 2 Pi bonds
Collision Theory
Particles must move toward each other
Particles must hit with proper orientation
Particles must hit with sufficiently high energy
Particles will separate after reaction occurs
Eareverse
∆H + Eaforward
Catalyst
lowers the activation hill
does NOT change the PE of the products of reactants
does NOT change ∆H
does NOT affect EQBM
Activation Energy
k=Ae^-Ea/RT
R = 8.314 J/molK. Ea = J/mol. T = K. A = frequency factor
Differential Rate Law
K = L^(n-1)/mol^(n-1)s
“0” change in [] does not affect anything
“1” [] changes, so does the rate (double [], double rate)
“2” [] changes, the rate is squared (double [], x4 rate., triple [], x9 rate)
Equilibrium constant
nA + mB ↔ pC + qD
K=([C]^p[D]^q)/([A]^n[B]^m)
Knew = (Koriginal)⁻¹ →rxn flips
Knew = (Koriginal)^n →n = factor
Kp = K(RT)^∆n → R=.08206 ∆n = coefficients of prod. – react.
Reaction Quotient
Q=([C]₀^p[D]₀^q)/([A]₀^n[B]₀^m)
Q=K system already at equilibrium
Q>K system will shift LEFT, too may products
Q
Change in pressure
P↑P↓→side w/ more less gas ions
P↓P↑→side w/ more gas ions
Change in temperature
heat↑heat↓→side w/o heat
heat↓heat↑→side w/ heat
Change in concentration
→opposite side