The half-life for radioactive decay of 14C is 5730 years. A wood sample contains only 80% of the 14C .The age of the wood sample would be-
1. 1898 years
2. 1765 years
3. 1931 years
4. 1860 years
The rate constant for the decomposition of hydrocarbons is 2.418 × 10–5 s–1 at 546 K. If the energy of activation is 179.9 kJ/mol, the value of the pre-exponential factor will be:
For a reaction A → Product, with k = 2.0 × 10–2 s–1, if the initial concentration of A is 1.0 mol L-1, the concentration of A after 100 seconds would be :
1. | 0.23 mol L-1 | 2. | 0.18 mol L-1 |
3. | 0.11 mol L-1 | 4. | 0.13 mol L-1 |
The decomposition of sucrose follows the first-order rate law. For this decomposition, t1/2 is 3.00 hours. The fraction of a sample of sucrose that remains after 8 hours would be:
1. | 0.13 | 2. | 0.42 |
3. | 0.16 | 4. | 0.25 |
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 rate constant for the first-order decomposition of H2O2 is given by the equation: \(log \ k \ = \ 14.34 \ - \ 1.25 \ \times \ 10^{4}\frac{K}{T}\). The value of Ea for the reaction would be:
1. 249.34 kJ mol-1
2. 242.64 J mol-1
3. -275.68 kJ mol-1
4. 239.34 kJ mol-1
The decomposition of A into the product has a value of k as 4.5 × 103 s–1 at 10°C and energy of activation of 60 kJ mol–1. The temperature at which the rate constant becomes 1.5 × 104 s–1 would be -
The rate of a reaction quadruples when the temperature changes from 293 K to 313 K. The energy of activation of the reaction would be -
1. 65.93 kJ mol-1
2. 52.85 kJ mol-1
3. 55.46 kJ mol-1
4. 60.93 kJ mol-1
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 x 10-4 mol L-1 s-1 and 5.5 x 10-4 mol L-1 s-1
2. 2.5 x 10-4 mol L-1 s-1 and 7.5 x 10-4 mol L-1 s-1
3. 1.5 x 10-4 mol L-1 s-1 and 4.5 x 10-4 mol L-1 s-1
4. 0.5 x 10-4 mol L-1 s-1 and 3.5 x 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-1min-2
4. bar-1/2min-1