50-mol sample of HI is placed in a 1.00-L vessel at 460C, and the reaction system is allowed to come to equilibrium. The HI partially decomposes,…

A 2.50-mol sample of HI is placed in a 1.00-L vessel at 460°C, and the reaction system is allowed to come to equilibrium. The HI partially decomposes, forming 0.190 mol H2 and 0.190 mol I2 at equilibrium. What is the equilibrium constant Kc for the following reaction at 460°C?
1/2 H2(g) + 1/2 I2(g) HI(g)
answer options:
1.23 × 102
8.10 × 10-3
1.72 × 10-2
11.1
7.63