Percent Composition of Compounds

Basic Concept

Mass percentage composition of a element in a compound is defined as percent mass of such element over the total mass of the compound.

Mass Percentage Composition (%) = Total atomic mass of a element / molecular weight

Feature Overview

With input of a molecular formula and mass (moles) of the compound, this module outputs the molecular weight, the number of molecules, mass percentages of each atom.

In addition to the problem solving module, the "Show Work" is also displayed along with the solution to illustrate the step-by-step guide in how your problem has been solved.

User Instructions

This is one step process, enter the known data and press Calculate to output the unknowns.

1. Select The Mole and Molecular Weight from the front page. The Input and Output screen appears.

2. Under Input Molecular Formula, enter the formula of the compound. Optionally, you can also enter the mass or moles of this compound.

Here is the typing instruction:

3. Click Calculate to output the results in red.

The percent composition of the compound is now shown in the table above.

The "Show Work" page of this problem is now displayed side-by-side with the solution in explaining how your problem has been solved in the step-by-step fashion.

4. To restart, click Reset.