Consider the reaction.

Question

Consider the reaction.

A(aq) ⇌ 2 B(aq) K = 2.54 x 10^-6 at 500 K

If a 5.00 M sample of A is heated to 500K, what is the concentration of B at equilibrium?

[B] = _____ M

Answer 1

A <==> 2B

K = [B]² / [A]

A <==> 2B

5.00......0.....Initial

-x........+2x...Change

5-x.....2x.....Equilibrium

2.54x10^-6 = (2x)² / 5-x

4x² = 1.27x10^-5 - 2.54x10^-6x

x² = 3.175x10^-6 - 6.35x10^-7

x = 1.59x10^-6 M

[B] = 2x = (2)(1.59x10^-6) = 3.18x10^-6 M