Hydrogen iodide can decompose into hydrogen and iodine gases.
2HI(g) ⇌ H₂(g) + I₂(g)
K for the reaction is 0.016.If 0.148 atm of HI(g) is sealed in a flask,what is the pressure of each gas when equilibrium is established?

Question

Quizplus · Accepted Answer

Using the ICE table method and the equilibrium constant (K), we can calculate the equilibrium pressures. Let x be the amount of HI that decomposes. At equilibrium, [HI] = 0.148 - 2x, [H2] = x, and [I2] = x. The K expression is K = ([H2][I2])/([HI]^2) = 0.016. Solving for x gives the pressures of HI, H2, and I2 as 0.118 atm, 0.015 atm, and 0.015 atm, respectively.

Hydrogen Iodide Can Decompose into Hydrogen and Iodine Gases