Calculate The Percentage Composition Of Each Of The Following Compounds

Calculating the percentage composition of compounds is crucial in chemistry to understand the makeup of substances. This calculator helps you determine the composition of compounds by mass and mole percentage.

1. Select the compound from the dropdown menu.
2. Enter the number of moles of the compound.
3. Click the “Calculate” button.

The formula to calculate the mass percentage of an element in a compound is:

Mass Percentage = (Mass of the element in the formula / Molar Mass of the compound) * 100

The formula to calculate the mole percentage is:

Mole Percentage = (Moles of the element in the formula / Total moles of the compound) * 100

Comparison of Mass and Mole Percentages of H2O

Element	Mass Percentage	Mole Percentage
H	11.19%	66.67%
O	88.81%	33.33%

• Always use the exact formula for the compound when calculating percentages.
• Rounded values may not add up to 100% due to rounding errors.

What is the difference between mass percentage and mole percentage?

Mass percentage is based on the mass of the element in the compound, while mole percentage is based on the number of moles of the element in the compound.

For more information, see the following authoritative sources:

• Chemistry World
• Britannica