Chem 1312, Exam 1

Molarity

mol solute / L solution

Molality

(moles of solute) / (kg of solvent)

Mole Fraction

(# moles solute) / (Total # of moles)

Mass Percent

(Mass of solute) / (Mass of solution) x100

Henry’s Law

C = kP

where C: concentration of the dissolved gas

P: partial pressure of the gaseous solute

Raoult’s Law (vapor pressure)

P_solution = X_solvent . P^*_{vapor pressure of pure solvent}

if they ask for 2 just add the results together

Boiling Point Elevation

_changeT = K_bm_solute

Freezing Point Depression

_changeT = K_fm_solute

Osmotic Pressure

pi_{osmotic p} = MRT

R: 0.08206

T in kelvin

i

(moles of particles in solution) / (moles of solute dissolved)

rate

(over the same temperature)

[A]_t2 - [A]_t1 / t₂ - t₁ = k[A]ⁿ

Order of reaction

n + m + l ….

Arrehenius Equation for 1

Arrehenius Equation for 2

0 order Rate Law

Rate = k

[A] = -kt + [A]₀

T_1/2 = [A]₀ / 2k

units: M/S

1st Order Rate Law

rate = k[A]¹

ln[A] = -kT + ln[A]₀

T_1/2 = 0.693 / k

units: s^-1

2nd Order rate law

rate = k[A]²

1/[A] = kt + 1/[A]₀

T_1/2 = 1/k[A]₀

units: M^-1S^-1

K

Equilibium Constant

on a reaction

jA + kB >< lC +mD

the law mass action = picture

reverse Kc

1/Kc

Kc when there is a coefficient (n) multiplying the equation

K_cⁿ

pressure and concentraiton equation

P = CRT

C: concentration (M)

Equilibrium of Partial Pressure in a gas

Kp

(same as Kc but with partial pressures)

Kc in terms of Kp

K = K_p(RT)^-changen

change in n = product coefficients - reactant coefficients

Q = K

Equilibrium

Q > K

shift to the left

consuming products and creating reactants

Q < K

shift to the right

consuming reactants and creating products

I.C.E shift to the right

-x of the reactants

I.C.E shift to the left

-x to the products

Quadratic Formula

x = (-b ± √(b²-4ac)) / (2a)