3. H2(g) + I2(g) 2 HI(g)
Kc=100.

Equimolar amounts of H2(g) and I2(g) are pumped into a previously evacuated, rigid 1.0 L container and allowed to attain the equilibrium shown above at a constant temperature. If 0.600 mol of HI(g) is present at equilibrium, how many moles of H2(g) were initially added to the container?