What will be the final pressure (approximately)? — Thermodynamics and Thermochemistry Chemistry Question

💡 Solution & Explanation

Initial moles = $1\text{ (H}_2\text{)} + 0.5\text{ (O}_2\text{)} + 2\text{ (N}_2\text{)} = 3.5\text{ moles}$. Final moles = $1\text{ (H}_2\text{O)} + 2\text{ (N}_2\text{)} = 3.0\text{ moles}$. Volume is constant. $P_2 = P_1 \times (n_2 / n_1) \times (T_2 / T_1) = 1\text{ atm} \times (3.0 / 3.5) \times (2940\text{ K} / 298\text{ K}) = 8.45\text{ atm} \approx 8.5\text{ atm}$.