chapter 6. CHEMICAL KINETICS class 12 chemistry textbook solution

4. Solve

iv. What is the energy of activation of a reaction whose rate constant doubles when the temperature changes from 303 K to 313 K? (54.66 kJ/mol)

Answer:- 

Given:

Rate constants; k2 = 2k1,

Temperatures: T1 = 303 K, T2 = 313 K

To find:

Activation energy of the reaction (Ea)

Formula:

log10 (k2/k1) = Ea / (2.303R) × ((T2 - T1) / (T2T1))

Calculation:

log10 (2k1/k1) = Ea / (2.303 × 8.314 J K-1 mol-1) × ((313 K - 303 K) / (313 K × 303 K))

log10 2 = Ea / (2.303 × 8.314 J mol-1 K-1) × (10 / (313 × 303))

0.3010 = Ea / (19.147 J mol-1) × 1.0544 × 10-4

Ea = (0.3010 × 19.147) / (1.0544 × 10-4) J mol-1

Ea = 54659 J mol-1 = 54.66 kJ mol-1

The energy of activation of the reaction is 54.66 kJ mol-1.

chapter 6. CHEMICAL KINETICS class 12 chemistry textbook solution page 137