Chemistry

Chemistry

Problem

At 500 K, the equilibrium constant KpK_p for the reaction N2(g)+3H2(g)⇌2NH3(g)\text{N}_2(g) + 3\text{H}_2(g) \rightleftharpoons 2\text{NH}_3(g) is 5.6×1035.6\times10^{3}. Determine KpK_p for 12N2(g)+32H2(g)⇌NH3(g)\tfrac{1}{2}\text{N}_2(g) + \tfrac{3}{2}\text{H}_2(g) \rightleftharpoons \text{NH}_3(g) at the same temperature.
Intuitive explanation

The key insight is that equilibrium constants scale predictably when you change the stoichiometric coefficients of a reaction. If you multiply all coefficients by a factor, you raise KpK_p to that same power; if you divide coefficients, you take the corresponding root. Here, the second reaction is exactly half the first, so you need to take the square root of the original KpK_p.

Intuitive explanation

The key insight is that equilibrium constants scale predictably when you change the stoichiometric coefficients of a reaction. If you multiply all coefficients by a factor, you raise KpK_p to that same power; if you divide coefficients, you take the corresponding root. Here, the second reaction is exactly half the first, so you need to take the square root of the original KpK_p.

Browse the problem library