Limiting Reagent

1.15g of sodium reacts with an excess of chlorine forming sodium chloride. In this reaction, one reactant is in excess and the other will be completely used up.The reaction will stop when sodium - the limiting reactant - is used up.

The limiting reactant is the reactant that will be completely used up in a reaction and stop the reaction.

To determine which reactant is limiting, work out the number of moles of each reactant and divide by the number of moles in the balanced equation(stoichiometry).The smaller number gives the limiting reactant.Example:
1.15g of sodium reacts with 5.32g of chlorine
2Na(s) + Cl₂(g) → 2NaCl(s)

	Na	Cl2
moles	1.15  23	5.32  71
	0.05	0.075
moles ÷ stoichiometry	0.05   2	0.075    1
	0.025	0.075

So chlorine is in excess.