Consider the reaction represented by the equation: 2SO\(_{2(g)}\) + O\(_{2(g)}\) ⇌ 2SO\(_{3(g)}\); ∆H = - 197 kJmol\(^{-1}\). Which of the following conditions will not increase the yield of sulphur (VI) oxide?

A.

Increase in temperature

B.

Decrease in temperature

C.

Increase in pressure

D.

Addition of O2 into the mixture

Correct answer is A

The reaction is an exothermic reaction (∆H=-197kjmol).
For continual yield of sulphur(IV)oxide, heat must be liberated.
So,increasing the temperature of the reaction will lead to reduction in yield of \(SO_3\) since it favours backward reaction which is endothermic.