A Study of the System, H₂(g)+ I₂(g) 2HI(g), Was

A study of the system, H₂(g) + I₂(g) 2HI(g) , was carried out. K_c = 54.9 at 699.0 K for this reaction. A system was charged with 2.50 moles of HI in a 5.00-liter vessel as the only component initially. The system attained equilibrium at 699.0 K. How many moles of H₂(g) should there be in the container at that time?Hint: Be sure to find molarities of all reactants and products before plugging in to the equilibrium law and solving for the amount of H₂.

A) 0.337 moles
B) 1.25 moles
C) 0.297 moles
D) 0.500 moles
E) 0.266 moles