What volume of HCl gas is produced by the reaction of 2.4 liters of H2 gas with 1.5 liters of Cl2 gas? (Volumes are at the same T and P.)

Question

1. 3.0 liters
2. 4.8 liters
3. 0.75 liters
4. 2.4 liters
5. 1.5 liters

Answer 1

H2 + Cl2 ==> 2HCl

2.4L H2 will produce 2*2.4 = 4.8 L HCl if it has an excess of Cl2.

1.5 L Cl2 will produce 2*1.5 = 3.0 L HCl if it has an excess of H2.

This is a limiting reagent problem; I know that because BOTH reactants are given. Therefore, the amount HCl produced will be the smaller value (3.0L HCl) and Cl2 is the limiting reagent. H2 gas will be in excess. You can calculate, easily, the amount of H2 not reacted.
1.5 L Cl2 x (1 mole H2/1 mole Cl2) = 1.5 moles H2 used. We had 2.4 moles H2 initially; therefore, we have left 2.4-1.5 = ?? L H2 unreacted.