LO 22 - 28 Flashcards
Van Hoff’s Factor (i) = ________
mols particles in solution/mols formula units dissolved
When is Van Hoff’s Factor (i) used?
the solute is a strong electrolyte
Equation for freezing point depression when an electrolyte is used
ΔTf = m ⋅ Kf ⋅ i
Equation for boiling point elevation when an electrolyte is used
ΔTb = m ⋅ Kb ⋅ i
Equation for osmotic pressure when an electrolyte is used
Π = M ⋅ R ⋅ T ⋅ i
The greater the concentration of particles in a reaction, the _____ the rate
greater
Increasing temperature of a reaction, _______ rate of reaction
increases
Reactions in which reactants must collide in a specific orientation typically have a _______ rate of reaction
slower
Average rate of the reaction _________ as the reaction progresses because reactant concentrations _______
decreases, decrease
standard Rate Law
rate = k ⋅ [A] ^n
- k constant
- [A] concentration
- n reaction order
Rate law for a zero-order reaction
rate = k ⋅ [A] ^0 = k
Rate law for a first-order reaction
rate = k ⋅ [A]^1
Rate law for a second-order reaction
rate = k ⋅ [A]^2
The order of a reaction can only be determined __________
experimentally
Rate law for multiple reactants A and B
rate = k ⋅ [A]^m ⋅ [B]^n
- m order for A
- n order for B
The overall order of a reaction
The sum of each reaction order for the reactants i.e. (m + n)
The integrated rate law relates ________ to _________
concentrations of reactants to time
The rate law relates __________ to _________
concentrations of reactants to rate
Integrated rate law for zero-order reactions
[A]t = -kt + [A]0
The straight-line plot of a zero-order reaction
y axis - [A]t
x axis - time
Integrated rate law for first-order reactions
ln([A]t / [A]0) = -kt
ln [A]t = -kt + ln[A]0
The straight-line plot of a first-order reaction
y axis - ln[A]t
x axis - time
Integrated rate law for second-order reactions
1/[A]t = kt + 1/[A]0
The straight-line plot of a second-order reaction
y axis - 1/[A]t
x axis - time
The ___________ is the time required for the concentration of a reactant to reach 1/2 its initial value
half life
Half-life equation for zero order reaction
t1/2 = [A]0 / (2k)
Half-life equation for first order reaction
t1/2 = 0.693 / k
Half-life equation for second order reaction
t1/2 = 1 / (k ⋅ [A]0)
The half-life of a first order reaction is _______
constant
The half-life of a second order reaction ________ as concentration decreases
increases (gets longer)
The half-life of a zero-order reaction ________ as concentration decreases
decreases (gets shorter)
Units for k in a zero order reaction?
M ⋅ s-1
Units for k in a first order reaction?
s-1
Units for k in a second order reaction?
M-1 ⋅ s-1
Each consecutive half life for a 2nd order reaction is _______
Doubled
Each consecutive half life for a 0 order reaction is ______
halved
Given a graph of concentration over time, k is the absolute value of . . .
slope
