In a reaction with second-order kinetics where molecules X convert to Y, increasing the concentration
of X to three times its original value will affect the rate of Y formation by which factor?
1. 6 times
2. 9 times
3. 12 times
4. 3 times
The rate of a chemical reaction doubles when the temperature increases by 10 K (from 298 K). What is the activation energy of the reaction?
1. 65.6 Jmol-1
2. 52.9 kJmol-1
3. 45.9 kJmol-1
4. 35.7 Jmol-1
The activation energy for the reaction 2HI(g) → H2(g)+ I2(g) is 209.5 kJ mol−1 at 581K. What is the fraction of molecules of reactants having energy equal to or greater than activation energy?
The rate constant for a first order reaction is 60 s–1. How much time will it take to reduce the initial concentration of the reactant to its 1/16th value?
A first-order reaction takes 40 min for 30 % decomposition. The half life of the reaction will be:
1. | 88.8 min | 2. | 94.3 min |
3. | 67.2 min | 4. | 77.7 min |
The rate constant for the decomposition of hydrocarbons is 2.418 × 10–5 s–1 at 546 K. If the energy of activation is 179.9 kJ/mol,
the value of the pre-exponential factor will be:
1.
2.
3.
4.
For a reaction A → Product, with k = 2.0 × 10–2 s–1, if the initial concentration of A is 1.0 mol L–1, the concentration of A after 100 seconds would be :
1. | 0.23 mol L–1 | 2. | 0.18 mol L–1 |
3. | 0.11 mol L–1 | 4. | 0.13 mol L–1 |
The decomposition of sucrose follows the first-order rate law. For this decomposition, t1/2 is 3.00 hours. The fraction of a sample of sucrose that remains after 8 hours would be:
1. | 0.13 | 2. | 0.42 |
3. | 0.16 | 4. | 0.25 |
The decomposition of hydrocarbons follows the equation: k = (4.5 × 1011s–1) e–28000K/T
The activation energy (Ea) for the reaction would be:
1. 232.79 kJ mol–1
2. 245.86 kJ mol–1
3. 126.12 kJ mol–1
4. 242.51 kJ mol–1
The rate constant for the first-order decomposition of H2O2 is given by the equation:
\(log \ k \ = \ 14.34 \ - \ 1.25 \ \times \ 10^{4}\frac{K}{T}\).
The value of Ea for the reaction would be:
1. 249.34 kJ mol–1
2. 242.64 J mol–1
3. –275.68 kJ mol–1
4. 239.34 kJ mol–1