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

Subtopic:  First Order Reaction Kinetics |
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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:

$1.$ $4.0$ $×$ ${10}^{12}$ ${\mathrm{s}}^{-1}$
$2.$ $7.8$ $×$ ${10}^{-13}$ ${\mathrm{s}}^{-1}$
$3.$ $3.8$ $×$ ${10}^{-12}$ ${\mathrm{s}}^{-1}$
$4.$ $4.7$ $×$ ${10}^{12}$ ${\mathrm{s}}^{-1}$

Subtopic:  Arrhenius Equation |
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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
Subtopic:  First Order Reaction Kinetics |
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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
Subtopic:  First Order Reaction Kinetics |
54%
From NCERT
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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
Subtopic:  Arrhenius Equation |
73%
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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

Subtopic:  Arrhenius Equation |
56%
From NCERT
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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 × 10s–1   would be -

1. $$24 \text { K}$$
2. $$24 ^\circ \text { K}$$
3. $$31 ^\circ \text { K}$$
4. $$38 ^\circ \text { K}$$

Subtopic:  Arrhenius Equation |
63%
From NCERT
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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

Subtopic:  Arrhenius Equation |
71%
From NCERT
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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

Subtopic:  Definition, Rate Constant, Rate Law |
79%
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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

Subtopic:  Definition, Rate Constant, Rate Law |
77%
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