How many moles of aluminum are needed to make 9 moles of molecular hydrogen? Given the reaction: 2 Al + 6 HCl → 2 AlCl3 + 3H2

We need 6.0 moles of aluminium

Explanation:

Step 1: Data given

Number of moles of H2 = 9.0 moles

Step 2: The balanced equation

2 Al + 6 HCl → 2 AlCl3 + 3H2

Step 3: Calculate moles Al

For 2 moles Aluminium, we need 6 moles HCl to produce 2 moles AlCl3 and 3 moles H2

For 9.0 moles of H2 we need 2/3 * 9.0 = 6.0 moles of aluminium

We need 6.0 moles of aluminium