Question

Which of the following conditions is the most suitable for manufacture of sulfuric acid in contact process?

(a) High temperature and high pressure

(b) Low temperature and high pressure

(c) High pressure and low temperature

(d) Low pressure and low temperature

The question was asked during a job interview.

This intriguing question originated from P-Block Elements topic in portion P-Block Elements of Chemistry – Class 12

Answer 1

Correct answer is (b) Low temperature and high pressure

Explanation: Since the forward reaction is exothermic, lower temperatures will favor higher yield. This is in accordance with the Le Chatelier’s principle that an equilibrium tends to attain its original form when external conditions are changed. Since the reactant is in gas phase, increasing pressure increases yield.