Q. No.When a biochemical reaction is carried out in a laboratory outside the human body in the absence of an enzyme, then the rate of reaction obtained is times. The activation energy of a reaction in the presence of an enzyme is:
1.
2. P is required.
3. Different from obtained in the laboratory.
4. Data is insufficient.
1.
2. P is required.
3. Different from obtained in the laboratory.
4. Data is insufficient.
The activation energy for a simple chemical reaction A → B is Ea in a forward direction. The activation energy for the reverse reaction:
1. Is negative of Ea
2. Is always less than Ea
3. Can be less than or more than Ea
4. Is always double of Ea
The reaction A → B follows first-order kinetics. The time taken for 0.8 mol of A to produce 0.6 mol of B is 1 hour. The time taken for the conversion of 0.9 mol of A to produce 0.675 mol of B will be:
| 1. | 1 hour | 2. | 0.5 hour |
| 3. | 0.25 hour | 4. | 2 hour |
If the rate of the reaction is equal to the rate constant, the order of the reaction is:
| 1. | 0 | 2. | 1 |
| 3. | 2 | 4. | 3 |
The temperature dependence of the rate constant (k) of a chemical reaction is written in terms of the Arrhenius equation,
k = A.e–E*/RT. The activation energy (E*) of the reaction can be calculated by plotting:
1.
2.
3.
4.
The radioisotope, tritium has a half-life of 12.3 years. If the initial amount of tritium is 32 mg, how many milligrams of it would remain after 49.2 years:
| 1. | 1 mg | 2. | 2 mg |
| 3. | 4 mg | 4. | 8 mg |
The decomposition of NH3 on a platinum surface is a zero-order reaction. The rates of production of N2 and H2 will be respectively:
(given ; k = 2.5 × 10–4 mol–1 L s–1 )
| 1. | 2.5 × 10−4 mol L−1 s−1 and 5.5 × 10−4 mol L−1 s−1
|
| 2. | 2.5 × 10−4 mol L−1 s−1 and 7.5 × 10−4 mol L−1 s−1
|
| 3. | 1.5 × 10−4 mol L−1 s−1 and 4.5 × 10−4 mol L−1 s−1
|
| 4. | 0.5 × 10−4 mol L−1 s−1 and 3.5 × 10−4 mol L−1 s−1 |
The rate equation of a reaction is expressed as, Rate = \(k(P_{CH_{3}OCH_{3}})^{\frac{3}{2}}\)
(Unit of rate = bar min–1)
The units of the rate constant will be:
1. bar1/2 min
2. bar2 min–1
3. bar–1 min–2
4. bar–1/2 min–1
The factor(s) that affect the rate of a chemical reaction is/are:
| 1. | Concentration/Pressure of reactants. |
| 2. | Temperature. |
| 3. | Presence of a catalyst. |
| 4. | All of the above. |
The correct statement about the rate constant of a reaction is:
| 1. | Rate constant is nearly doubled with a rise in temperature by 10 °C |
| 2. | Rate constant becomes half with a rise in temperature by 10 °C |
| 3. | Rate constant remains unchanged with a rise in temperature by 10 °C |
| 4. | None of the above |
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