Problem: Equal numbers of moles of H2 and I2 were mixed in a 3 liter flask and heated to 700 C. The initial concentration of each gas was 0.0088 M. They reacted according to the reaction H2(g) + I2(g) ⇄ 2 HI(g). 78.6% of the I2 was consumed in reaching equilibrium. What is Kc for the reaction?A. 0.25B. 530C. 4.2x10-5D. 4.0E. insufficient information is given to solve the problem

FREE Expert Solution

We are being asked to calculate the equilibrium constant, Kc for the given equilibrium reaction:

H2(g) + I2(g) ⇄ 2 HI(g)

When dealing with equilibrium and Kc:

Kc → equilibrium units are in molarity
Kc is an equilibrium expression:

$\overline{){{\mathbf{K}}}_{{\mathbf{c}}}{\mathbf{=}}\frac{\mathbf{products}}{\mathbf{reactants}}}$

only aqueous and gaseous species are included in the equilibrium expression
▪ the coefficient of each compound in the reaction equation will be the exponent of the concentrations in the equilibrium expression

Given:

Initial Concentrations:

[H2] = 0.0088 M
[I2] = 0.0088 M
[HI] = 0 M

Problem Details

Equal numbers of moles of H2 and I2 were mixed in a 3 liter flask and heated to 700 C. The initial concentration of each gas was 0.0088 M. They reacted according to the reaction H2(g) + I2(g) ⇄ 2 HI(g). 78.6% of the I2 was consumed in reaching equilibrium. What is Kc for the reaction?

A. 0.25

B. 530

C. 4.2x10-5

D. 4.0

E. insufficient information is given to solve the problem