Question

Which is the limiting reactant when 3.5 g of al and 5.6 g of cl2 react?

Answer 1

The limiting reactant is Cl₂.

You use the usual method for finding limiting reactants.

In your problem, the balanced equation is

2Al + 3Cl₂ → 2AlCl₃

From Al: 3.5 g Al × `"1 mol Al"/"26.98 g Al" × ("2 mol AlCl"_3)/"2 mol Al"` = 0.130 mol AlCl₃

From Cl₂: 5.6 g Cl₂ × `("1 mol Cl"_2)/("70.91 g Cl"_2) × ("2 mol AlCl"_3)/("3 mol Cl"_2)`# = 0.0526 mol AlCl₃

So the limiting reactant is Cl₂.