Worksheet: Rate Laws from Initial Rates
In this worksheet, we will practice using measurements of initial rate to deduce the rate law of a reaction and the order of reaction for each reactant.
Q1:
In a reaction between compounds and , doubling the concentration of increases the rate of reaction by a factor of 4. However, tripling the concentration of reactant increases the rate by a factor of 3.
What is the order of reaction with respect to ?
What is the order of reaction with respect to ?
Q2:
In a reaction between compounds and , quadrupling the concentration of doubles the rate of reaction. However, doubling the concentration of reactant increases the rate by a factor of 8.
What is the order of reaction with respect to ?
- A1
- B
- C2
- D
- E4
What is the order of reaction with respect to ?
Q3:
Hypochlorite and iodide ions react to form hypoiodite and chloride ions: The initial rate of reaction was measured at three different reactant concentrations, as shown in the table.
| (M) | (M) | Initial Rate (M/s) |
|---|---|---|
Determine the rate law for this reaction.
- A Rate =
- BRate =
- CRate =
- DRate =
- ERate =
Determine the appropriate units for the rate constant of this reaction, .
- A L2/mol2⋅s
- B L3/mol3⋅s
- C L/mol⋅s
- D s−1
- E M/s
Expressing concentrations in molars and time in seconds, estimate, to 3 significant figures, the numerical value of the rate constant, .
- A
- B
- C
- D
- E
Q4:
Nitric oxide reacts with chlorine to form nitrosyl chloride : The initial rate of reaction of nitric oxide was measured at three different reactant concentrations, as shown in the table.
| (M) | (M) | Initial Rate (M/s) |
|---|---|---|
| 0.100 | 0.100 | |
| 0.100 | 0.150 | |
| 0.150 | 0.100 |
Determine the rate law for this reaction.
- A Rate =
- BRate =
- CRate =
- DRate =
- ERate =
Determine the appropriate unit for the rate constant of this reaction, .
- A L2/mol2⋅s
- B L3/mol3⋅s
- C L/mol⋅s
- D s−1
- E M/s
Expressing concentrations in units of molars and times in units of seconds, estimate, to 3 significant figures, the numerical value of the rate constant, .
Q5:
| Time (s) | 4.00 | 8.00 | 12.0 | 16.0 | 20.0 |
|---|---|---|---|---|---|
| (M) | 0.220 | 0.144 | 0.110 | 0.088 | 0.074 |
By plotting suitable functions of the tabulated data, determine the appropriate unit for the rate constant of this reaction.
- A L2/mol2⋅s
- B s−1
- C M/s
- D L/mol⋅s
- E L3/mol3⋅s
Expressing concentrations in molars and time in seconds, estimate, to 3 significant figures, the numerical value of the rate constant for this reaction.