## Excess Reactant Calculation

Meigan Wu 2E
Posts: 66
Joined: Fri Sep 28, 2018 12:29 am
Been upvoted: 1 time

### Excess Reactant Calculation

What are the steps to finding the excess of a reactant in a chemical reaction?

Ariel Cheng 2I
Posts: 67
Joined: Fri Sep 28, 2018 12:29 am

### Re: Excess Reactant Calculation

After identifying the limiting reactant, determine how much of the other reactant is used up by converting the grams of the limiting reactant to moles and, using the stoichiometric coefficients for the ratio, determining how many moles of the other reactant is used up. Convert that number to grams and using simple subtraction from how many grams of the excess reactant is given, you should be able to find how much excess there is!

Sydney To 1D
Posts: 60
Joined: Fri Sep 28, 2018 12:15 am

### Re: Excess Reactant Calculation

After balancing the equation for the reaction, calculate the molar masses for each of the reactants and products. Then convert the known masses of the reactant and products to moles. In order to identify the limiting and excess reagents, compare the calculated moles to required moles to determine the limiting reagent. The limiting reagent is the reactant in which the calculated moles is larger the the value of the the moles given (need>have), thus limiting the amount of product formed. The excess reagent is the reactant in which the value of moles given is larger than the value of the calculated moles (have>need).