Aluminum metal reacts with hydrochloric acid to produce solid aluminum chloride and hydrogen gas. how many moles of aluminum are needed to produce 1.2 moles of hydrogen gas?

Moles of Aluminum needed : 0.8

Given

1.2 moles H₂

Required

moles of aluminum

Solution

The reaction coefficient in a chemical equation shows the mole ratio of the components of the compounds involved in the reaction (reactants and products)

Reaction(balanced equation)

2Al + 6 HCl = 2AlCl₃ + 3H₂

From the equation, mol ratio of Al : H₂ = 2 : 3, so mol Al :

= 2/3 x mol H₂

= 2/3 x 1.2

= 0.8 moles