Question

Consider the following reaction

A(aq) yields 3B (aq) K_c= 6.45 x 10^-6 at 500 K

If a 3.20 M sample of A is heated to 500 K, then what is the concentration of B at equilibrium?

Answer 1

                             A -----> 2B

initial                    3.2         0

change               -x            +2X

at equilibrium       3.2-x      +2x

Kc = [B]²/[A]

6.45*10^-6 =( 2x)² /3.2-x

2.064*10^-5 -6.45*10^-6x = 4x²

4x² + 0.00000645x-0.00002064 =0

x = 0.00227

[B] = 2x = 2*0.00227 = 0.00454M >>>> answer