Chemical Kinetics

Consider the following reaction A + B C The time taken for A to become 1/4th of its initial concentration is twice the time taken to become 1/2 of the same. Also, when the change of concentration of B is plotted against time, the resulting graph gives a straight line with a negative slope and a positive intercept on the concentration axis. The overall order of the reaction is .

For a reaction A K1 B K2 C. If the rate of formation of B is set to be zero then the concentration of B is given by :

1. (K1 - K2)[A]
2. (K1 + K2)[A]
3. K1K2[A]
4. (K1/K2)[A]

Time required for 99.9\% completion of a first order reaction is times the time required for completion of 90\% reaction.(nearest integer)

Consider the two different first order reactions given below A + B C (Reaction 1) P Q (Reaction 2) The ratio of the half life of Reaction 1 : Reaction 2 is 5 : 2. If t1 and t2 represent the time taken to complete 2/3rd and 4/5th of Reaction 1 and Reaction 2, respectively, then the value of the ratio t1 : t2 is 10-1 (nearest integer). [Given : 10(3) = 0.477 and 10(5) = 0.699]

During kinetic study of reaction 2A + B C + D, the following results were obtained : [figure] Based on above data, overall order of the reaction is .

Consider the following single step reaction in gas phase at constant temperature. 2A(g) + B(g) C(g) The initial rate of the reaction is recorded as r1 when the reaction starts with 1.5 atm pressure of A and 0.7 atm pressure of B. After some time, the rate r2 is recorded when the pressure of C becomes 0.5 atm. The ratio r1 : r2 is 10-1. (Nearest integer)

Consider the following transformation involving first order elementary reaction in each step at constant temperature as shown below. [figure] Some details of the above reactions are listed below. [figure] If the overall rate constant of the above transformation (k) is given as k = k1k2k3 and the overall activation energy (Ea) is 400 kJ mol-1, then the value of Ea3 is kJ mol-1 (nearest integer)

Consider the following reaction, the rate expression of which is given below A + B C rate = k[A]1/2[B]1/2 The reaction is initiated by taking 1 M concentration of A and B each. If the rate constant (k) is 4.6 10-2 s-1, then the time taken for A to become 0.1 M is sec. (nearest integer)

The ratio of 14C12C in a piece of wood is 18 part that of atmosphere. If half life of 14C is 5730 years, the age of wood sample is years.

The following data were obtained during the first order thermal decomposition of a gas A at constant volume : A(g) 2B(g) + C(g) [figure] The rate constant of the reaction is 10-2 s-1 (nearest integer)