Chemical Kinetics · Question 36

What is the activation energy for a reaction if its rate doubles when the temperature is raised from 20 C to 35 C? (R = 8.314 J mol-1 K-1)

1. 34.7 kJ mol-1
2. 15.1 kJ mol-1
3. 342 kJ mol-1
4. 269 kJ mol-1

For a reaction between A and B the order with respect to A is 2 and the order with respect to B is 3. The concentrations of both A and B are doubled, the rate will increase by a factor of

1. 12
2. 16
3. 32
4. 10

A reaction is 50\% complete in 2 hours and 75\% complete in 4 hours. The order of reaction is

1. 1
2. 2
3. 3
4. 0

Activation energy (Ea) and rate constants (k1 and k2) of a chemical reaction at two different temperatures (T1 and T2) are related by

1. k2k1 = - EaR ( 1T1 - 1T2 )
2. k2k1 = - EaR ( 1T2 - 1T1 )
3. k2k1 = - EaR ( 1T2 + 1T1 )
4. k2k1 = EaR ( 1T1 - 1T2 )

In a reaction, A + B product, rate is doubled when the concentration of B is doubled, and rate increases by a factor of 8 when the concentrations of both the reactants (A and B) are doubled, rate law for the reaction can be written as

1. rate = k[A][B]2
2. rate = k[A]2[B]2
3. rate = k[A][B]
4. rate = k[A]2[B]

In a zero-order reaction, for every 10 rise of temperature, the rate is doubled. If the temperature is increased from 10 to 100 , the rate of the reaction will become

1. 256 times
2. 512 times
3. 64 times
4. 128 times

The rate of the reaction: 2N2O5 4NO2 + O2 can be written in three ways. -d[N2O5]dt = k [N2O5] d[NO2]dt = k' [N2O5]; d[O2]dt = k'' [N2O5] The relationship between k and k' and between k and k'' are

1. k' = 2k; k'' = k
2. k' = 2k; k'' = k/2
3. k' = 2k; k'' = 2k
4. k' = k; k'' = k

The unit of rate constant for a zero order reaction is

1. mol L-1 s-1
2. L mol-1 s-1
3. L2 mol-2 s-1
4. s-1

The half-life of a substance in a certain enzyme-catalysed reaction is 138 s. 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. 414 s
2. 552 s
3. 690 s
4. 276 s

Which one of the following statements for the order of a reaction is incorrect?

1. Order can be determined only experimentally.
2. Order is not influenced by stoichiometric coefficient of the reactants.
3. Order of a reaction is sum of power to the concentration terms of reactants to express the rate of reaction.
4. Order of reaction is always whole number.