Question

How many grams of hydrogen chloride would be produced from 0.49g of hydrogen and 50g of chlorine
H2 +Cl2->2Hcl

Answer 1

This is a limiting reagent (LR) problem. You know that when more than one amount is given for the reagents.
H2 + Cl2->2HCl
moles H2 = g/molar mass = 0.49/2 = 0.245
moles Cl2 = 50/71 = 0.704
0.245 mols H2 COULD produce 0.245 x 2 = 0.49 moles HCl.
0.704 mols Cl COULD produce 0.704 x 2 = 1.41 moles HCl.
With LR problems the SMALLER number of moles of product is the winner; therefore, H2 is the LR and 0.49 moles HCl will be formed.
grams HCl = moles HCl x molar mass HCl = ?
Post your work if you get stuck.