Answer:
74.04 liters of hydrogen gas are produced.
Explanation: According to reaction, 2 mol of HCl gas gives 1 mole of hydrogen gas, then 6 moles of HCl gas will give: moles of hydrogen gas that is 3 moles.
The pressure of the hydrogen gas at 298 K = 0.990 atm
The volume occupied by the hydrogen gas = V
Number of hydrogen has moles = 3 moles
PV=nRT
V = 74.04 L
74.04 liters of hydrogen gas are produced.