AP Chemistry Review (Unit 1-3)

Empirical formula rhyme

percent to mass, mass to mole, divide by small, multiply til whole

get the simplest whole # ratio of the moles in the compound

Molecular formula

whole # multiple of the empirical formula ratio

% yield

actual/theoretical

% error

(experimental - theoretical)/theoretical

The amount of product for a reaction is determined by the [] reactant

limiting reactant

Combustion reactions make

CO2 and H2O

compounds can be separated by [] []

chemical changes

mixtures can be separated by [] changes

physical

filtration separates mixtures based on differences in [] []. The large particles are trapped on the filter paper while the soluble component goes through the filter paper and stays in the []

particle size; filtrate

mass is conserved during [] and [] changes

physical; chemical

Group 1 metals and [] are soluble. They are usually the [] in a chemical reaction

NH4+; spectators

When reading a volume of a liquid in a container, you can estimate by reading [] the []. That can give you one more sig. fig. in your volume

in between; graduated markings

Ranking measuring devices from least precise to most precise

1. beaker

2. graduated cylinder

3. volumetric flasks

4. burette

Density

mass/volume

The % composition by mass for a pure compound []

does not change

Gas mixtures are [] because of the [] of the particles

homogeneous; constant random motion

Gases are [] because of the [] between the particles

compressible; large spaces

Gas pressure is caused by [] with the [] of the container. More collisions or more energetic collisions = more pressure

collisions of particles; walls

1 atm

760 torr/mmHg

P and V

inversely related

T and V

directly related

T and P

directly related

T =

Kelvin

V =

L

P =

atm

R =

.08206

1 mole of gas = [] L at STP

22.4 L at STP

Gas pressure and # of moles are [] related

directly

M = dRT/P; what is d?

d = density in g/L

The more molar mass a gas has, the [] it moves at a given temperature

slower

T = (not units)

average kinetic energy

Collecting a gas by water displacement

Ptotal = Pdrygas + Pwatervapor

Real gases behave most like an ideal gas at [] and []

high temperature; low pressure

The more [] a gas is or [] a gas is, the more it will [] from ideal behavior

polar; larger; deviate

Keq = [products]^x/[reactants]^y; x and y?

coefficients in the balanced chemical equation

Only [] and [] appear in an equilibrium expression

aq; g

Use [] for molarity and [] for atm

[ ]; (Pgas)

A large Keq means that there are more [] at equilibrium; a small Keq means there are more [] at equilibrium

products; reactants

Reversing a reaction

1/Keq

Doubling a reaction

Keq^2

Adding reactions

Multiply the K's together

La Chatelier's Principle: all about determining []

Q

If Keq > Q, reaction shifts to the []

right

[] and [] DO NOT shift an equilibrium

Catalysts; inert gases

Changes in [] can only shift an equilibrium if the [] are different on each side

pressure; # of gas particles

An increase in [] favors a shift in the equilibrium towards the side with [] moles of gas

pressure; less

If you are given [] concentrations/pressures, use [] to determine equilibrium conditions

initial; RICE table

In Ksp expressions, there is no []

denominator

X is the [] of the sparingly soluble salt. Pay attention to ratios between salt and each ion

molar solubility

2 ions - Ksp =

3 ions - Ksp =

x^2; 4x^3

The larger the x value, the more [] the salt is

soluble

You can only directly compare Ksp's to solubility when the [] are the []

Ksp expressions; same

If Ksp [] Q, a precipitate forms

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