1. obj. assign

2. 1. In the reaction A + B Products, if B is taken in excess, then it is example of
Second order reaction
(2) Zero order reaction
(3) Pseudounimolecular reaction
(4) First order reaction

3. 2. Which of the following is correct for a first order reaction?
t1/2 a (2) t1/2 1/a
(3) t1/2 a (4) t1/2 1/a2

4. 3. Half–life of a reaction is found to be inversely proportional to the cube of initial concentration. The order of reaction is
(2) 3
(3) (4) 5

5. The half-life for the reaction
N2O NO O2 is 24hrs at 30°C. Starting with 10 g
of N2O5 how many grams of N2O5 will remain after a period of 96 hours?
1.25 g (2) 0.63 g
(3) 1.77 g (4) 0.5 g

6. 5. For a given reaction, t1/2 = 1/Ka, the order of this reaction is
(2) 1
(3) (4) 3

7. 6. The half life of a first order reaction is 10 min
6. The half life of a first order reaction is 10 min. If initial amount of 0.08 mol/litre and concentration at some instant is 0.01 mol/litre, then t =
10 min (2) 30 min
(3) 20 min (4) 40 min

8. 7. If 75% of first order reaction is completed in 32 min, then 50% of the reaction would be completed in
16 min (2) 24 min
(3) 10 min (4) 20 min

9. 8. In a first order reaction, 75% of the reactant disappeared in 1
8. In a first order reaction, 75% of the reactant disappeared in hours. Calculate the rate constant of the reaction
3.6 × 10–3 s– (2) 2.8 × 10–4s–1
(3) 7.2 × 10–3 s– (4) 1.8 × 10–3 s–1

10. 9. The rate of constant for a first order reaction whose half–life is 480 sec. is
2.88 × 10–3 sec–1 (2) 1.44 × 10–3 sec–1
(3) 1.44 sec– (4) 0.72 × 10–3 sec–1

11. 10. In a first order reaction, the rate constant is 0. 693 hr–1
10. In a first order reaction, the rate constant is hr–1. The half-life of the reaction is
0.693 hr (2) 1 hr
(3) 9.63 hr (4) 69.3 hr

12. 11. The temperature coefficient of most of the reactions lies between
1 and (2) 2 and 3
(3) 1 and (4) 2 and 4

13. 12. The rate of reaction is doubled for every 10° rise is temperature
12. The rate of reaction is doubled for every 10° rise is temperature. The increase in reaction rate as a result of temperature rise from 10° to 100° is
(2) 512
(3) (4)614

14. 13. The rate of chemical reaction is doubled for every 10°C rise in temperature because of
Increase in the activation energy
(2) Decrease in the activation energy
(3) Increase in the number of molecular collision
(4) Increase in the number of activated molecules

15. 14. A chemical reaction was carried out at 300 K and 280 K
14. A chemical reaction was carried out at 300 K and 280 K. The rate constants were found to be K1 and K2 respectively. Then
K2 = 4K (2) K2 = 2K1
(3) K2 = 0.25 K (4) K2 = 0.5 K1

16. 15. The minimum energy necessary to permit a reaction is
Internal energy (2) Threshold energy
(3) Activation energy (4) Free energy

17. 16. The minimum energy required for the reacting molecules to undergo reaction is
Potential energy (2) Kinetic energy
(3) Thermal energy (4) Activation energy

18. 17. The rate constant (K/) of one of the reaction is found to be double that of the rate of constant (K//) of another reaction. Then the relationship between the corresponding activation energies of the two reactions (Ea/ and Ea//) can be represented as
Ea/ > Ea// (2) Ea/ < Ea//
(3) Ea/ = Ea// (4) Ea/ < 4Ea//

19. 18. An endothermic reaction A B has an activation energy 15 kcal/mole and energy of reaction 5 kcal/mole. The activation energy of the reaction B A is
(1) 20 kcal/mole (2) 15 kcal/mole
(3) 10 kcal/mole (4) None of these

20. 19. Minimum energy of activation of an exothermic reaction is
Zero (2) Negative
(3) Positive (4) Either of the three

21. 20. For an endothermic reaction, where DH represents the enthalpy of the reaction of kJ/mol, the minimum value for the energy of activation will be
Less than DH (2) Zero
(3) More than DH (4) Equal to DH

22. Thank You