For a reaction A → B, the Arrhenius equation is given as \(log_{e}k \ = \ 4 \ - \ \frac{1000}{T}\) the activation energy in J/mol for the given reaction will be:
1. 8314
2. 2000
3. 2814
4. 3412
Select the correct option based on statements below:
Assertion (A): | For elementary reactions, the law of mass action and the rate of law expression are generally the same. |
Reason (R): | The molecularity of an elementary reaction is always one. |
1. | Both (A) and (R) are true and (R) is the correct explanation of (A). |
2. | Both (A) and (R) are true but (R) is not the correct explanation of (A). |
3. | (A) is true but (R) is false. |
4. | Both (A) and (R) are false. |
If a reaction A + B → C is exothermic to the extent of 30 kJ mol−1 and the forward reaction has an activation energy of 249 kJ mol−1, the activation energy for the reverse reaction in kJ mol-1 will be:
1. | 324 | 2. | 279 |
3. | 40 | 4. | 100 |
The rate constant for a first-order reaction is . The time required to reduce 2.0 g of the reactant to 0.2 g will be:
1. | 200 s | 2. | 500 s |
3. | 1000 s | 4. | 100 s |
For a reaction of the type 2A + B 2C, the rate of the reaction is given by . When the volume of the reaction vessel is reduced to th of the original volume, the rate of reaction changes by a factor of -
1. 0.25
2. 16
3. 64
4. 4
For a general reaction A B, the plot of the concentration of A vs. time is given in the figure.
The slope of the curve will be:
1. | -k | 2. | -k/2 |
3. | -k2 | 4. | -k/3 |
The rate of a reaction doubles when its temperature changes from 300 K to 310 K. The activation energy of such a reaction will be:
\((R=8.314 \mathrm{~J} \mathrm{~K}^{-1} \mathrm{~mol}^{-1} \text { and } \log 2=0.301)\)
1. | \(53.6 \mathrm{~kJ} \mathrm{~mol}^{-1} \) | 2. | \(68.6 \mathrm{~kJ} \mathrm{~mol}^{-1} \) |
3. | \(59.5 \mathrm{~kJ} \mathrm{~mol}^{-1} \) | 4. | \(70.5 \mathrm{~kJ} \mathrm{~mol}^{-1}\) |
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 role of a catalyst is to change:
1. | Gibbs energy of the reaction |
2. | Enthalpy of reaction |
3. | The activation energy of the reaction |
4. | Equilibrium constant |
The correct statement based on the graph below is:
1. | The activation energy of the forward reaction is E1 + E2 and the product is less stable than reactant. |
2. | The activation energy of the forward reaction is E1 + E2 and the product is more stable than the reactant. |
3. | The activation energy of both forward and backward reaction is E1 + E2 and reactant is more stable than the product. |
4. | The activation energy of the backward reaction is E1 and the product is more stable than reactant. |