Question

What is an excess reactant?

Answer 1

Hint : When chemical bonds between atoms are formed or dissolved, chemical reactions occur. The reactants are the compounds that go into a chemical reaction, and the results are the substances that come out of the reaction.

Complete Step By Step Answer:
A reactant that is present in excess of the amount needed to mix with all of the limiting reactants is known as an excess reactant. As a result, after all of the limiting reactants have been absorbed, an excess reactant remains in the reaction mixture.
The percentage excess is determined by dividing the quantity of excess material by the quantity needed to consume the limiting reactant completely:
$M$ : moles present
${M_0}$ :moles required to react completely with the limiting reagent
$\% excess = \dfrac{{(M - {M_0})}}{{{M_0}}} \times 100$ .

Note :
In a chemical reaction, as one of the reactants is depleted, the reaction abruptly comes to a halt. To calculate the amount of product made,we should decide which reactant will reduce the chemical reaction (the limiting reagent) and the reactant will be in excess (the excess reagent). Calculating the amount of product that each reactant will form is one way to find the limiting reagent; the one that generates the least product is the limiting reagent.