Chemical Kinetics · Question 12

Rate constants of a reaction at 500 K and 700 K are 0.04 s-1 and 0.14 s-1, respectively; then, activation energy of the reaction is : (Given: 3.5 = 0.5441, R = 8.31 J K-1 mol-1)

1. 182310 J
2. 18500 J
3. 18219 J
4. 18030 J

For a certain reaction, the rate = k[A]2[B], when the initial concentration of A is tripled keeping concentration of B constant, the initial rate would

1. increase by a factor of six
2. increase by a factor of nine
3. increase by a factor of three
4. decrease by a factor of nine

Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R. In the light of the above statements, choose the correct answer from the options given below:

1. Both A and R are true but R is NOT the correct explanation of A.
2. A is true but R is false.
3. A is false but R is true.
4. Both A and R are true and R is the correct explanation of A.

The given graph is a representation of kinetics of a reaction [figure] The y and x axes for zero and first order reactions, respectively are

1. zero order (y = concentration and x = time), first order (y = t1/2 and x = concentration)
2. zero order (y = concentration and x = time), first order (y = rate constant and x = concentration)
3. zero order (y = rate and x = concentration), first order (y = t1/2 and x = concentration)
4. zero order (y = rate and x = concentration), first order (y = rate and x = t1/2)

For a first order reaction A Products, initial concentration of A is 0.1 M, which becomes 0.001 M after 5 minutes. Rate constant for the reaction in min-1 is

1. 1.3818
2. 0.9212
3. 0.4606
4. 0.2303

The half life of a first order reaction is 2000 years. If the concentration after 8000 years is 0.02 M, then the initial concentration was :

1. 0.04 M
2. 0.16 M
3. 0.32 M
4. 0.08 M

For a chemical reaction 4A + 3B 6C + 9D Rate of formation of C is 6 10-2 mol L-1 s-1 and rate of disappearance of A is 4 10-2 mol L-1 s-1. The rate of reaction and amount of B consumed in interval of 10 seconds, respectively will be :

1. 10 10-2 mol L-1 s-1 and 30 10-2 mol L-1
2. 1 10-2 mol L-1 s-1 and 30 10-2 mol L-1
3. 10 10-2 mol L-1 s-1 and 10 10-2 mol L-1
4. 1 10-2 mol L-1 s-1 and 10 10-2 mol L-1

For a reaction, A B, enthalpy of reaction is -4.2 kJ mol-1 and enthalpy of activation is 9.6 kJ mol-1. The correct potential energy profile for the reaction is shown in option.

1. [figure]
2. [figure]
3. [figure]
4. [figure]

The slope of Arrhenius plot ( ln k v/s 1T ) of first order reaction is -5 103 K. The value of Ea of the reaction is. Choose the correct option for your answer. [Given R = 8.314 J K-1 mol-1]

1. -83 kJ mol-1
2. 41.5 kJ mol-1
3. 83.0 kJ mol-1
4. 166 kJ mol-1

An increase in the concentration of the reactants of a reaction leads to change in :

1. heat of reaction
2. threshold energy
3. collision frequency
4. activation energy