#### Chemical Kinetics Three Marks Questions

12th Standard EM

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Chemistry

Time : 01:00:00 Hrs
Total Marks : 30
10 x 3 = 30
1. The rate of formation of a dimer in a second order reaction is 7.5 X 10-3mol L-1 s-1 monomer concentration. Calculate the rate constant.

2. For a reaction x+y+z$\longrightarrow$ productsthe rate law is given by ratek =k[x]3/2[y]1/2 what is the overall order of the reaction and what is the order of the reaction with respect to z.

3. Explain briefly the collision theory of bimolecular reactions

4. Write Arrhenius equation and explains the terms involved

5. The decomposition of Cl2O7 at 500K in the gas phase to Cl2 and O2 is a first order reaction. After 1 minute at 500K, the pressure of Cl2O7 falls from 0.08 to 0.04 atm. Calculate the rate constant in s-1

6. Hydrolysis of methyl acetate in aqueous solution has been studied by titrating the liberated acetic acid against sodium hydroxide. The concentration of an ester at different temperatures is given below.

t(min) 0 20 40 60
v (ml) 20.2 25.6 29.5 32.8 50.4

Show that the reaction is the first order reactions.

7. Identify the order for the following reactions
(i) Rusting of Iron
(iii) $2A+3B\longrightarrow products$;rate k[A]1/2[B]2

8. For the reaction $2x+y\longrightarrow L$find the rate law from the following data.

 [x] (min) [y] (min) rate (Ms-1) 0.2 0.02 0.15 0.4 0.02 0.30 0.4 0.08 1.20 0.4 0.08 1.20
9. (ii) The half life of a first order reaction x ⇾products is 6.932 x 104 s at 500K. What percentage of x would be decomposed on heating at 500K for 100 min. (e0.06 = 1.06).

10. Show that in case of first order reaction, the time required for 99.9% completion is nearly ten times the time required for half completion of the reaction.