An equilibrium mixture contains 0.810 mol HI, 0.170 mol I2, and 0.200 mol H2 in a 1.00-L flask. What is the equilibrium constant for the following reaction?
2HI(g) H2(g) + I2(g)
How many moles of I2 must be removed in order to double the number of moles of H2 at equilibrium?