General
✓✗A first order reaction A(g) → B(g) + C(g) has a half-life of 15 min. Starting with pure A at 0.80 atm (constant volume), the total pressure after 45 min is
- 1.40 atm
- 1.50 atm
- 1.60 atm
- 0.90 atm
General
✓✗A catalyst does NOT change
- the rate of reaction
- the activation energy
- the Gibbs energy change (ΔG) of the reaction
- the path of the reaction
General
✓✗In a complex reaction, the overall rate is determined by the
- fastest step
- first step always
- last step
- slowest step
General
✓✗A first order reaction has a specific reaction rate of 10−2 s−1. How much time will it take for 20 g of the reactant to reduce to 5 g?
- 138.6 s
- 693.0 s
- 346.5 s
- 238.6 s
General
✓✗Which of the following plots is a straight line for a first order reaction?
- [R]2 vs t
- 1/[R] vs t
- [R] vs t
- ln[R] vs t
General
✓✗The order of a reaction with rate = k[A]1/2[B]3/2 is
- 1
- 1.5
- 3
- 2
General
✓✗For the reaction 4NH3 + 5O2 → 4NO + 6H2O, NO forms at 3.6 × 10−3 mol L−1 s−1. The rate of formation of water (in units of 10−3 mol L−1 s−1) is
- 2.4
- 5.4
- 3.6
- 7.2
General
✓✗The half-life of a first order reaction is 30 min. The fraction of the reactant remaining after 1 hour 30 min is
- 0.250
- 0.062
- 0.333
- 0.125
General
✓✗For a reaction A → B, the enthalpy of reaction is −4.2 kJ mol−1 and the enthalpy of activation is 9.6 kJ mol−1. The correct potential energy profile for the reaction is
General
✓✗For a reaction A → products, the rate becomes 4 times when [A] is doubled. The order of the reaction is
- 1
- 0
- 4
- 2
General
✓✗For a reaction R → P, the average rate between t = 0 and t = 20 min is 0.004 mol L−1 min−1. If [R]0 = 0.12 mol L−1, the concentration of R after 20 min is
- 0.08 mol L−1
- 0.116 mol L−1
- 0.10 mol L−1
- 0.04 mol L−1
General
✓✗For a gaseous reaction, the rate may be expressed in the unit
- atm s−1
- atm2
- s−1 atm−1
- atm
General
✓✗Match List I (quantity) with List II (expression).
Choose the correct answer from the options given below.
| List I | List II |
| P. Half-life, zero order | I. 0.693/k |
| Q. Half-life, first order | II. [R]0/k |
| R. Time for completion, zero order | III. 2.303/k |
| S. Time for 90% completion, first order | IV. [R]0/2k |
- P-IV, Q-I, R-II, S-III
- P-II, Q-I, R-IV, S-III
- P-IV, Q-III, R-II, S-I
- P-I, Q-IV, R-II, S-III
General
✓✗For a zero order reaction, the integrated rate equation is
- [R] = [R]0 − kt
- ln[R] = ln[R]0 − kt
- [R] = [R]0ekt
- 1/[R] = 1/[R]0 + kt
General
✓✗The elementary reaction 2HI → H2 + I2 is
- of molecularity zero
- termolecular
- bimolecular
- unimolecular