Limiting Reagents 
Reactant- A substance taking part in a chemical reaction
Molar mass- Molar mass is the weight of one mole (or 6.02 x 1023 molecules) of any chemical compounds
Limiting Reagent- the reactant in a chemical reaction that limits the amount of product that can be formed. Once all of the limiting reactant is used, the reaction will stop.
Theoretical yield- The term in chemistry that is used to refer to using limiting reagents; it is the amount of something you can make in theory with the reactants.
Actual yield- is the amount of substance that is really produced in a chemical reaction.
Percentage yield  is a measure of how successful a reaction is. 

                                For example, if my theoretical yield is 100g and when I do the reaction I only get 75g, my percentage yield will be 75% because only
                                75% of the theoretical yield was actually produced.