Q. No.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
(given ; k = 2.5 × 10–4 mol–1 L 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 |
| t/s | 0 | 30 | 60 | 90 |
| [Ester]/mol L–1 | 0.55 | 0.31 | 0.17 | 0.085 |
A reaction is first-order with respect to A and second-order with respect to B. The concentration of B is increased three times. The new rate of the reaction would:
| 1. | Decrease 9 times | 2. | Increase 9 times |
| 3. | Increase 6 times | 4. | Decrease 6 times |
In a reaction between A and B, the initial rate of reaction (r0) was measured for different initial concentrations of A and B as given below:
| A / mol L–1 | 0.20 | 0.20 | 0.40 |
| B / mol L–1 | 0.30 | 0.10 | 0.05 |
| ro / mol L–1 s–1 | 5.07 × 10–5 | 5.07 × 10–5 | 1.43 × 10–4 |
The order of the reaction with respect to A and B would be:
| 1. | The order with respect to A is 0.5 and with respect to B is zero |
| 2. | The order with respect to A is 1 and with respect to B is 0.5 |
| 3. | The order with respect to A is 2 and with respect to B is 1 |
| 4. | The order with respect to A is 1.5 and with respect to B is zero |
For a reaction, 2A + B → C + D, the following observations were recorded:
| Experiment | [A]/mol L–1 | [B]/mol L–1 | Initial rate of formation of D/mol L–1 min–1 |
| I | 0.1 | 0.1 | 6.0 × 10–3 |
| II | 0.3 | 0.2 | 7.2 × 10–2 |
| III | 0.3 | 0.4 | 2.88 × 10–1 |
| IV | 0.4 | 0.1 | 2.40 × 10–2 |
The rate law applicable to the above mentioned reaction would be:
1. Rate = k[A]2[B]3
2. Rate = k[A][B]2
3. Rate = k[A]2[B]
4. Rate = k[A][B]
Given the following observations:
| Experiment | [A] / mol L–1 | [B] / mol L–1 | Initial rate / mol L–1 min–1 |
| I | 0.1 | 0.1 | 2.0 × 10–2 |
| II | X | 0.2 | 4.0 × 10–2 |
| III | 0.4 | 0.4 | Y |
The reaction between A and B is first-order with respect to A and zero-order with respect to B. The values of X and Y are, respectively:
1. X = 0.2 \(mol\) \(L^{- 1}\); Y = \(\) \(0 . 08\) \(mol\) \(L^{- 1} \left(min\right)^{- 1}\)
2. X = 0.02 \(mol\) \(L^{- 1}\); Y = \(\) \(0 . 08\) \(mol\) \(L^{- 1} \left(min\right)^{- 1}\)
3. X = 0.01 \(mol\) \(L^{- 1}\); Y = \(\) \(0 . 8\) \(mol\) \(L^{- 1} \left(min\right)^{- 1}\)
4. X = 0.2 \(mol\) \(L^{- 1}\); Y = \(\) \(0 . 8\) \(mol\) \(L^{- 1} \left(min\right)^{- 1}\)
A radioactive substance has a rate constant of \(4 \, \text{years}^{-1}\). What is its half-life?
1. 0.05 years
2. 0.17 years
3. 0.26
4. 1.6 years
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