Percent Composition

Hello!!

We are going to talk about Percent Compositions!!!

(Isn't that what we use to calculate our marks?? you ask.)

Well... Kind of :)

It is actually: percentage by mass of a species in a chemical formula

Imagine a fruit pie that consists of strawberries, blueberries and blackberries.

and try to figure out how much of the pie is strawberry, blueberry or blackberry.

So back to chemistry.

Eg. What is the percentage composition of H^20?

Always assume you have 1 mole.

Total molar mass is 18g/mol

Molar mass of H^2 is 2g

                      O      is 16g

H^2 =  2g/ 18g  *  100%  =  11.1%

0      = 16/18g  * 100% = 88.9%

The results should  add up to 100%.

This is basically percent compositions!

see ya later!