5. When doing an experiment, aside from doing calculations, what can you do to

determine which reactant is the limiting reactant and which is the excess

reactant? *

check which reactant is totally consumed and which one remains in the mixture

Explanation:

Apart from doing calculations during an experiment, one can determine which reactant is limiting and which one is in excess by checking the resulting mixture for the presence of reactants.

A limiting reactant is one that determines the amount of product formed during a reaction. It is usually a reactant that is lower than stoichiometry amount.

On the other hand, an excess reactant is one that is present in more than the stoichiometrically required amount during a reaction.

Limiting reactants will be totally consumed in a reaction while excess reactant would still be seen present in mixture after the reaction has stopped.

Hence, apart from using stoichiometric calculation to determine which reactant is limiting or in excess during an experiment, one can just check the final mixture of the reaction for the presence of any of the reactants. The reactant that is detected is the excess reactant while the one without traces in the final mixture is the limiting reactant.

c. heat could easily travel through the molecules in the air and escape/enter the flask. removing the air slows down the heat transfer.