Using Limiting Reagents Intro.

Using a limiting reagent is a way to find how much of a substance you will gain, if the limiting reagent is limiting the amount that you can gain of the product through the process. For a simple example:

If you have 1g of H and 2g of O2, how many grams of water will you get?

H2+O2--> 2H2O


First you must find the limiting reagent.

H2

Moles= Grams/Molar Mass

Moles= 1/2

O2

Moles= Grams/Molar Mass

Moles=2/16

Moles= 1/8

Once you have found the limiting reagent, you must compare the molar ratio of the limiting reagent to the product.

It shows that for every one mole of oxygen which you have, you have 2 moles of H2O.

Moles= 1/8 X 2

Moles= 1/4 or .25

Then you must convert moles back into grams
Moles=Grams/Molar Mass (of H2O)

.25= Grams/18

Multiply by 18 on both sides and you will recieve your answer in grams.

Grams= 4.5