The reaction `2NO_((2)) g hArr N_2O_4(g) DeltaH`= negative occurring in a closed vessel attains equilibrium. If this vessel is kept in ice then which of the following change will be observed ?

Options

A. Equilibrium state will remain constant.
B. Increase in brown colour intensity in vessel.
C. The decrease in the concentration of product.
D. Decrease in brown colour intensity in vessel.

Answer

D

Explanation

Equilibrium reaction : `underset"Brown"(2NO_(2(g))) hArr underset"Colourless"(N_2O_(4(g))) DeltaH`=-ve
For this reaction `DeltaH=(-) ve`
`therefore` This is a endothermic reaction.
When the vessel is kept in ice, its temperature decreases. So, according to Le-chatelier.s principal to minimise the effect of decrease temp. The temp. should be increase and hence the reaction take place in forward direction and heat is release and new equilibrium is established.
When the new equilibrium is established then,
(1) The amount of product `N_2O_4` will increases
(ii) The amount of reactant `NO_2` (brown) will decreases.
i.e. Intensity of brown colour decreases.