In which of the following equilibrium system is the rate of the backward reaction favoured by increase of pressure

Options

A. `N_(2) + 3H_(2) hArr 2NH_(3)`
B. `N_(2) + O_(2) hArr 2NO`
C. `PCl_(5) hArr PCl_(3) + Cl_(2)`
D. `2SO_(2) + O_(2) hArr 2SO_(3)`

Answer

C

Explanation

According to Le Chatelier's principle if the pressure is increased, reaction will take place in a direction which will bring about a lowering of vapour pressure. This implies that equilibrium will shift in the direction which produces the smaller number of gas molecules