Q. No.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
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
An increase in the concentration of the reactants of a reaction leads to a change in:
| 1. | Heat of reaction | 2. | Threshold energy |
| 3. | Collision frequency | 4. | Activation energy |
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. |
At high pressure the following reaction is zero order-
The correct statements among the following is:
| (a) | Rate of reaction = Rate constant |
| (b) | Rate of the reaction depends on the concentration of ammonia |
| (c) | Rate of decomposition of ammonia will remain constant until ammonia disappears completely |
| (d) | Further increase in pressure will change the rate of reaction |
| 1. | (a, b, c) | 2. | (b, c, d) |
| 3. | (a, c, d) | 4. | (a, b, d) |
Match the graph given in Column I with the order of reaction given in Column II.
More than one item in Column I may be linked to the same item in Column II:
| Column I | Column II | ||
| (i) |  |
(a) | 1st order |
| (ii) |  |
(b) | Zero order |
| (iii) |  |
||
| (iv) |  |
||
| (i) | (ii) | (iii) | (iv) | |
| 1. | (a) | (b) | (a) | (b) |
| 2. | (a) | (b) | (b) | (a) |
| 3. | (a) | (a) | (b) | (b) |
| 4. | (b) | (b) | (a) | (a) |
The half-life for a zero-order reaction having 0.02 M initial concentration of reactant is 100 s. The rate constant (in mol L–1 s–1) for the reaction is:
1.
2.
3.
4.
What does ZAB represent in the collision theory of chemical reactions?
| 1. | The fraction of molecules with energies greater than Ea |
| 2. | The collision frequency of reactants, A and B |
| 3. | Steric factor |
| 4. | The fraction of molecules with energies equal to Ea |
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. |
For an lst order reaction, k = (8.5×105)e–15000K/T. The activation energy of the reaction is:
1. 150 kJ/mol
2. 125 kJ/mol
3. 50 kJ/mol
4. 500 kJ/mol
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