Mole chemical calculation

Question

When aluminum is placed in concentrated hydrochloric acid, hydrogen gas is produced 2Al(s)+6HCl(aq) 2AlCl 3 (aq)+3H 2 (g)

If you began this reaction with 5.50mol of aluminum, how many moles of hydrogen gas would be produced?

Answer 1

Hello, Aishat,

The balanced equation tells the answer to this question.

2Al(s) + 6HCl(aq) = 2AlCl₃(aq) + 3H₂(g)

We start with 5.5 moles of aluminum, Al. The balanced equation tells us the we'll get 3 moles of H₂ for every 2 moles of Al reactant. That's a molar ratio of 3/2 (moles H₂/moles Al). Use this as a conversion factor:

(5.5 moles Al)*(3 moles H₂/2 moles Al) = 8.25 moles H₂

I hope this helps,

Bob