Question

Assertion: Adding an inert gas todissociation equilibrium of gaseous $N _{2} O _{4}$ at constant pressure and temperature increases the dissociation.
Reason: Molar concentration of the reactants and products decreases on the addition of inert gas.

• A. If both A and R are correct and R is the correct explanation of A.
• B. If both A and R are correct but R is not the correct expalnation of A.
• C. A is true but R is false.
• D. A is false but R is true.

Answer 1

Answer: (B)

$\underset{( g )}{ N _{2} O _{4}} \rightleftharpoons 2 NO _{2}( g ) ; Q_{C} =\frac{\left[ NO _{2}\right]^{2}}{\left[ N _{2} O _{4}\right]}$
When inert gas is added under the condition of constant pressure, volume increases.
Hence, $Q_{C}$ decreases and reaction moves in forward direction to achieve equilibrium.