Question

One mole of N₂O₄ (g) at 300K is kept in a closed container under one atmosphere pressure. It is heated to 600K when 20% by mass of N₂O₄ (g) decomposes to NO₂ (g). The resultant pressure is

• A. 1.2 atm
• B. 2.4 atm
• C. 2 atm
• D. 1 atm

Answer 1

Answer: (B)

2.4 atm

Answer 2

N₂O₄ 2NO₂

Initial pressure of N₂O₄ at 600K,P_600K = $\frac { 1 } { 300 } \times 600$= 2 atm

N₂O₄ decomposes as follows

N₂O₄ 2NO₂

2(1–α) 2×2×α (given α = 0.2)

The resultant pressure = 2(1 + α) = 2 (1 + 0.2) = 2.4 atm