At the start of the reaction there are 0.714 mole of H2, 0.984 mole of I2, and 0.886 mole of HI in a 2.70 L reaction chamber. Calculate the concentrations of the gases at equilibrium. The equilibrium constant is 54.3.

See your other post. I made a typo, in that I used K = 53 and not 54.3