Chemical Calulations

4.3 From masses to balanced equations

Limiting Reactants

• When you do an experiment, often one of the reactants will be in excess. E.g. if you add HCl to Mg, H gas is given off and you see bubbles. If bubbles stop appearing but there is still Mg ribbon, the Mg is in excess. The reason the reaction's stopped is because all the acid has been used up. The HCl is the limiting reactant. 
• The reactant that gets used up first in a reaction is called the…