Slope of the graph given is \(-9.2 J/mol\). The activation energy of the reaction is :

Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → 175.8 J/mol
The Arrhenius equation k = A e−Ea/RT in logarithmic form is:
ln k = ln A − Ea/RT ⇒ log k = log A − Ea/(2.303 RT)
The graph in the question plots log k against 1/T, so its slope is −Ea/(2.303 R):
−Ea/(2.303 R) = −9.2
Ea = 9.2 × 2.303 × R
Ea = 9.2 × 2.303 × 8.3 J K−1 mol−1 ≈ 175.8 J mol−1
(With R = 8.314 J K−1 mol−1 the value is 176.2 J mol−1; the nearest option is 175.8 J/mol.)