Equilibrium constant

Question

Use the following reactions and their equilibrium constants to predict the equilibrium constant for this reaction:

2 A(s) ↔ 3 D(g).

A(s) ↔ 1⁄2 B(g) + C(g) K1 = 0.0334

3D(g)↔B(g)+2C(g) K2 =2.35

Answer 1

You might want to read about Hess's Law so you have a better idea of how to approach these problems.

Given:

(1). A(s) <==> 1/2 B(g) + C(g) K1 = 0.0334

(2). 3D(g) <==> B(g) + 2C(g) K2 = 2.35

Target equation:

2A(s) <==> 3D(g)

Procedure:

copy (1) and x2: 2A(s) <==> B(g) + 2C(g) K = (K1)² = (0.0334)² = 0.00112

reverse (2): B(g) + 2C(g) <==> 3D(g) K = 1/K2 = 1/2.35 = 0.426

Add together and combine/cancel like terms, to end up with...

2A(s) <==> 3D(g) TARGET EQUATION

K = 0.00122 x 0.426

K = 0.000520 = 5.20x10^-4