When computing the value of the equilibrium constant, the numbers substituted in the expression for Kc must be?

Kayla: When computing the value of the equilibrium constant, the numbers substituted in the expression for Kc must be?
When computing the value of the equilibrium constant, the numbers substituted in the expression for Kc must be the concentrations that are the
A. initial concentrations
B. amounts present at equilibrium
C. difference between the initial and equilibrium concentrations
D. sum of the initial and equilibrium concentrations
E. those given for the system

Answers and Views:

Answer by Nick
I believe it is the amounts present at equilibrium.