Topic - Chemical Kinetics 

Class - XII

1) For a first order reaction, the time required to reduce initial concentration by a factor of 1/4 is 25 sec. The time required to reduce initial concentration by a factor of 1/16 will be   

ANS: 50 sec

2) The rate of reaction increases by 2.15 times when the temperature is raised from 300 to 310 K, if k is the rate constant at 300 K then the rate constant at 310 K will be equal to     

ANS: 2.15×k

3) The half life period for a reaction was doubled when the initial concentration was doubled . The order of reaction is      

ANS: 0

4) For a first order reaction, the time taken to reduce initial concentration by a factor of 1/4 is 20 min. The time required to reduce initial concentration by a factor of 1/16 will be     

ANS: 40 min

5) For the reaction having rate law expression Rate=k[A] 3/2 [B] −1/2 If the concentration of both A and B are increased four time the rate of reaction    

ANS: Increases 4 times

6) A reaction is 75% complete i 32 min. The time required for 50% of the reaction to complete will be   

ANS: 16 min

7) Suppose that the rate law for a reaction is : Rate = k [A] [B] and that the initial concentration of A and B are equal. If c represent the concentration of both A and B at any time t, then a linear graph will result if :  

ANS: 1/c is plotted against t

8) The rate law of a reaction is : Rate = k [A]  [B]. On doubling the concentration of both A and B the rate 'x' will become    

ANS: 8x

9) How much first would a reaction proceed at 57 degree C than at 27 degree C. If activation energy is 83 KJ mol ^-1 ?     

ANS: 24.1 times

10) The elementary process for a reaction is: A (g) + 2B (g) -----> C (g) + D (g). In a experiment involving this reaction, the initial partial pressures of A and B are P(A)  = 0.60 atm and P(B) = 0.80 atm respectively. When P(C) = 0.20 atm , the rate of reaction relative to the initial rate is :     

ANS: 1/6