At a high temperature, equal concentrations of 0.160 mol/L of H2(g) and I2(g) are initially present in a flask. The H2 and I2 react according to the balanced equation below.
H2(g) + I2(g)    2 HI(g)
When equilibrium is reached, the concentration of H2(g) has decreased to 0.036 mol/L. What is the equilibrium constant, Kc, for the reaction?

18. At 25 C, 0.138 mg AgBr dissolves in 10.0 L of water. What is the equilibrium constant for the reaction below?
AgBr(s)    Ag+(aq) + Br–(aq)

a. 5.40 x 10–13
b. 5.40 x 10–11
c. 1.90 x 10–8
d. 7.35 x 10–7
e. 1.90 x 10–6