Which of the following statements about the rate constant, k, are correct?
I and II only
I and III only
II and III only
I, II and III
A student experimentally determined the rate expression for the reaction between iodine and propanone to be:
Rate = k [H+] [C3H6O]
Which graph is consistent with this information?
The rate information below was obtained for the following reaction at a constant temperature:
C2H5Br (aq) + OH- (aq) → C2H5OH (aq) + Br - (aq)
|
[C2H5Br] / mol dm-3 |
[OH-] / mol dm-3 |
Rate / mol dm-3 s-1 |
|
3.0 x 10-3 |
2.0 x 10-2 |
4.0 x 10-4 |
|
6.0 x 10-3 |
2.0 x 10-2 |
8.0 x 10-4 |
|
6.0 x 10-3 |
4.0 x 10-2 |
1.6 x 10-3 |
What are the orders of reaction with respect to C2H5Br and OH-?
C2H5Br is first order and OH- is first order
C2H5Br is first order and OH- is second order
C2H5Br is second order and OH-is first order
C2H5Br is second order and OH- is second order
The mechanism for the following reaction between iodine and propanone is shown.
CH3COCH3 (aq) + I2 (aq) → CH3COCH2I (aq) + HI (aq)
Step 1: CH3COCH3 + H+ → CH3COH+CH3
Step 2: CH3COH+CH3 → CH3COHCH2 + H+
Step 3: CH3COHCH2 + I2 → CH3COHCH2I + I-
Step 4: CH3COHCH2I → CH3COCH2I + H+
Which classifications of CH3COCH3, H+ and CH3COHCH2 are correct?
|
CH3COCH3 |
H+ |
CH3COHCH2 |
|
|
A |
Intermediate |
Intermediate |
Catalyst |
|
B |
Reactant |
Intermediate |
Product |
|
C |
Reactant |
Catalyst |
Intermediate |
|
D |
Reactant |
Product |
Intermediate |
The proposed mechanism for the following reaction where ethanal dimerises in dilute alkaline solution to form 3-hydroxybutanal is shown.
2CH3CHO → CH3CH(OH)CH2CHO
Step 1: CH3CHO + :OH- → :CH2CHO + H2O slow step
Step 2: CH3CHO + :CH2CHO → CH3CH(O:-)CH2CHO fast step
Step 3: CH3CH(O:-)CH2CHO + H2O → CH3CH(OH)CH2CHO + :OH- fast step
Which of the following statements is not correct?
The rate expression is rate = [CH3CHO] [OH-]
Step 1 is the rate-determining step
OH- is a catalyst
Steps 2 and 3 have a lower activation energy than step 1
