Percentage composition Indicates the relative amount of each element present in a compound.
Calculating percentage composition Step 1 : Calculate molar mass Step 2 : Divide the subtotal for each elements mass by the molar mass. Step 3: Multiply by 100 to convert to a percentage.
Example 1 1. Calculate the molar mass of water, H 2 O. Step 1 – H- 2(1.01)= 2.02 O – 1(16.0)= 16.0 ________ 18.02
Step /18.02 X 100 = 11.21% 16.0 /18.02 X 100 = % Water is composed of % hydrogen and % oxygen.
Example 2 Calculate the percentage composition of sucrose, C12H22O11.
Example 3 Find the percentage composition of hydrogen in sulfuric acid.