# Question c5bf1

Jan 16, 2014

You divide the moles of each substance by its coefficient of the balanced equation. The substance that has the smallest answer is the limiting reactant.

Consider the reaction:
2Al + 3I₂ → 2AlI₃

What is the limiting reactant if 1.20 g Al reacts with 2.40 g I₂?

Step 1: Convert all masses into moles.

1.20 g Al × $\frac{1 m o l A l}{26.98 g A l}$ = 0.0445 mol Al

2.40 g I₂ × (1 mol I₂)/(253.8 g I₂)# = 0.009 46 mol I₂

Step 2: Divide the moles of each substance by its coefficient in the balanced equation.

For Al: 0.0445/2 = 0.0222

For I₂: 0.00946/3 = 0.003 15

Since I₂ gives the smaller number, I₂ is the limiting reactant.

Here is a video which discusses how to determine limiting reactants.

video from: Noel Pauller