How to solve stoichiometry word problems

1) Mole-Mole Problems

Problem: How many moles of HCl are needed to react with 0.87 moles of Al?

Step 1: Balance The Equation & Calculate the Ratios 2Al:6HCl (1:3) 2Al:2AlCl3 (1:1) 2Al:3H2 (1:1.5) Step 2: Find the Moles of the Given 0.87 moles of aluminum are reacted with hydrochloric acid Step 3: Calculate the moles using the ratios moles HCl = 0.87molAl x 3molHCl/1molAl = 2.6 mol HC