CBSE Guess > Papers > Important Questions > Class XII > 2007 > Chemistry > Chemical Kinetics

Chemical Kinetics

1. Form the rate expression for the following reactions determine their order of reaction and dimensions of the rate constants.
   a) 3NO(g) --> N₂O(g) + NO₂ (g) Rate = K [NO]²
   b) H₂O₂ (aq) + 3 I ^- (aq) + 2H⁺ --> 2H₂O (l) + I-₁ Rate =- k [H₂O] [I-]
   c) CH₃ CHO(g) --> CH₄(g) + CO(g) Rate = k [CH₃ CHO]^3/2
   d) CHCl₃ (g) + Cl₂ (g) --> CCl₄ (g) + HCl (g): Rate = [CHCl₃] [Cl2] ^1/2
   e) C₂ H₅ Cl(g) --> C₂H₄(g) = HCl(g) : Rate = k [C₂H₅Cl]
2. A reaction is second order with respect to a reactant. How is the rate of reaction affected if the concentration of reactant is (I) doubled (ii) reduced to ½?
3. A reaction is first order in A and second order in B.
   i) Write differential rate equation.
   ii) How is the rate affected when concentration of B is tripled?
   iii) How is the rate affected when the concentration of both A and B is doubled?
4. In a reaction between A and B, the initial rate of reaction was measured for different initial concentration of A and B as given below.

   [A]/M [B]/M r0 / Ms-5

   0.2 0.3 5.07 x 10-5

   0.2 0.1 5.07 x 10-5

   0.4 0.05 7.6 x 10-5

5. Reaction between NO₂ and F₂ to give NO₂ F takes place by the following mechanism.
   NO₂ (g) + F₂(g) slow > NO₂ F(g) + F(g)
   NO₂(g) + F(g) fast > NO₂F(g)
   Write the rate expression for the reaction.
6. The following result has been obtained during the kinetic studies of the reaction.
   2A + B --> C+D
   Experiment [A]/M [B]/M initial rate of formation of D/Mmin^-1
   

   1 2 3 4

   0.1 0.3 0.3 0.4

   0.1 0.2 0.4 0.1

   6x 10-3 7.2x 10-2 2.88x 10-1 2.4x 10-2

   Determine the rate law and rate constant for the reaction.
7. The reaction between A and B is first order with respect to A and zero order with respect to B. fill in the blank in the following table.
   

   Experiment 1 2 3 4

   [A]/M 0.1 - 0.4 -

   [B]/M 0.1 0.2 0.4 0.2

   initial rate / M min-1 2x 10-2 4x 10-2 - 2x 10-2

8. The rate constant for a first order reaction 60 s^-1. How much time will it take to reduce the initial concentration of the reactant to its 1/16th value?
9. The rate of most of the reactions double when their temperature is raised from 298k to 308k. Calculate their activation energy

1. Atomic Structure and Chemical Bonding
2. Solid States
3. Solutions
4. Thermodoynamics
5. Chemical Kinetics
6. Nuclear Chemistry
7. Polymers
8. Biomolecules
9. Chemistry In Every Day Life