# What are limiting reactants?

Aug 30, 2017

Limiting reactants or limiting reagents decide the amount of product formed and the amount of excess reagent used.

#### Explanation:

A limiting reactant is that reactant that is completely used up in a reaction. It is found out by dividing the stoichiometric coefficients of the given reactants with the number of moles used.For example,
In the reaction below, if we take $2 m o l$ of ${N}_{2} \mathmr{and} {H}_{2}$,

${N}_{2 \left(g\right)} + 3 {H}_{2 \left(g\right)} r i g h t \le f t h a r p \infty n s 2 N {H}_{3 \left(g\right)}$

For ${N}_{2}$,

ratio is $\frac{2}{1}$

For ${H}_{2}$

ratio is $\frac{2}{3}$

The ratio for ${H}_{2}$ < ${N}_{2}$.So, for this reaction, ${H}_{2}$ is the limiting reactant and ${N}_{2}$ is the excess reactant i.e present in excess quantity