The equilibrium constant for HI decomposition at 500 °C is 5.8×10-3.

Question

2HI(g) > H2(g) + I2(g)

At that temperature reactants and products are gaseous. (There is no change in the total number of moles, so Kc = Kp.)
A sample of 0.49 mol of HI is placed in a 1.00 L vessel which is then heated to 500 °C. When equilibrium is reached, what is the molar concentration of H2? (Give units).
[H2] = 0.032 M

Now I cant figure out how to fine the concentrations of I2 and HI.
I keep getting for I2=.035M and for HI=.46M

Answer 1

see above.