Percent Composition Formula

Percent composition is the term used to describe the percent by mass of each element in a compound. It is typically found using the molar mass values for both the elements in the compound and the compound itself.

Percent Composition Formula Questions:

1.Find the percent composition of water.

Answer:

First, find the molar mass of water (H₂O).

H = 1.01 x 2 = 2.02         H₂O = 2.02 + 16.00 = 18.02

O = 16.00 x 1 =

Now find the percent composition of each element.

2. Find the percent composition of calcium nitrate, Ca(NO₃)₂.

Ca = 40.08 x 1 = 40.08            Ca(NO₃)₂ = 40.08 + 28.02 + 96.00 = 164.10

N = 14.01 x 2 = 28.02

O = 16.00 x 6 = 96.00