Question

The first order reaction \(N_2O_5 \to 2NO_2 + 1/2 O_2\), is carried out in a closed container and there were no products initially. When it is heated at constant volume the final pressure of the system on 75% completion of the reaction is

• A. 2.5 times initial pressure
• B. 3.5 times initial pressure
• C. 3 times initial pressure
• D. 2 times initial pressure

Hint:

A quick formula for total pressure at degree of dissociation \(\alpha\) is: \(P_t = P_0 [1 + (n-1)\alpha]\) where \(n\) is the total moles of product per mole of reactant.
Here, \(P_t = P_0 [1 + (2.5 - 1) \times 0.75] = P_0 [1 + 1.5 \times 0.75] = 2.125 P_0\).

Answer 1

The Correct Option is D