1B Reaction Orders

Question 1

For first order reactions:
1. Reaction rate is ______ in the concentration of one reactant
2. How does a first order reaction look like (also what is rate and rate law)

Answer 1

1. LINEAR
2. A —>Product (rate law =k[A, rate=-d[A]/dt])

Question 2

1. What is the first order integrated rate law (both versions) to find the concentration of A

Answer 2

1Integrated: [A]=[A]0 e^-kt OR ln[A]=ln[A]0-kt

Question 3

1. What is [A]t (subsript)
2. What is [A]0 (subscript)
3. What is the units for k for first order
4. How did the graphs of a first order differ from [A]t and ln[A]t

Answer 3

1. The concentration of A at time t
2. The concentration of A at t=0
3. K has units of s^-1 or 1/s
4. [A]t has exponential decay and ln[A]t is linearized

Question 4

What is the definition of a half life or t1/2

Answer 4

The time required for the concentration of a reactant to decrease to half of its initial concentration

Question 5

What is the half life equation for first order reactions (short and long way)

Answer 5

1. t1/2= .693/k
2. t1/2=ln2/k

Question 6

How is the speed of a reaction related to half life

Answer 6

1. Short half-life has a FAST REACTION
2. Long half life has a SLOW REACTION

Question 7

1. What is a lifetime (T)
2. What is the equation
3. When is lifetime ONLY meaningful
4. What equation shows relationship between half life (t 1/2) and lifetime (T)

Answer 7

1. The time required for the concentration of a reactant in a first-order reaction to decrease by a factor of e aka [A]=[A]0 /e
2. T=1/k
3. ONLY FOR FIRST ORDER REACTIONS
4. t1/2=Txln(2)

Question 8

For second order reactions:
1. Reaction rate is ______ in the concentration of one reactant
2. Reaction rate is ______ in the concentration of two reactant
3. Integrated rate law for 2nd order
4. Half life equation
5. K units

Answer 8

1. Reaction rate is QUADRATIC in the concentration of one reactant
2. Reaction rate is LINEAR in the concentration of two reactants
3. 1/[A]t=1/[A]0 + kt
4. t1/2=1/k[A]0
5. M^-1 s^-1 (1/M s)

Question 9

Zero Order reactions:
1. Reaction rate is _______ of the concentrations
2. Integrated rate law:
3. Units of k
4. Half life

Answer 9

1. Reaction rate is independent of the concentrations
2. [A]t=[A]0-kt
3. M/s
4. t1/2=[A]0/2k

Question 10

What is the rate of a zero order reaction

Answer 10

Rate=k