Q. No.The half-life of a certain enzyme catalysed reaction is 138 s, that follow the 1st order kinetics. The time required for the concentration of the substance to fall from 1.28 mg L–1 to 0.04 mg L–1, is:
1. 276 s
2. 414 s
3. 552 s
4. 690 s
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 |
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.
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
During a nuclear explosion, one of the products is 90Sr with a half-life of 28.1 years. If 1µg of 90Sr was absorbed in the bones of a newly born baby instead of calcium, the amount of 90Sr that will remain after 10 years in the now grown up child would be -
(Given ,antilog(0.108)=1.28)
1. 0.227 µg
2. 0.781 µg
3. 7.81 µg
4. 2.27 µg
NO2 required for a reaction is produced by the decomposition of N2O5 in CCl4 as per the equation,
2N2O5(g) 4NO2(g) + O2(g)
The initial concentration of N2O5 is 3.00 mol L–1 and it is 2.75 mol L–1 after 30 minutes. The rate of formation of NO2 is:
1. 2.083 × 10–3 mol L–1 min-1
2. 8.333 × 10–3 mol L–1 min-1
3. 4.167 ×10–3 mol L–1 min-1
4. 1.667 × 10–2 mol L–1 min-1
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) |
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) |
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