Percent Composition by Mass Problems

Front

What is percent composition by mass?

Back

Percent composition by mass is the percentage by mass of each element in a compound, calculated by dividing the mass of the element by the total mass of the compound and multiplying by 100.

Front

How do you calculate the total mass of a compound?

Back

To calculate the total mass of a compound, sum the atomic masses of all the atoms present in the chemical formula.

Front

What is the formula for calculating percent composition by mass?

Back

Percent Composition = (Mass of Element / Total Mass of Compound) x 100.

Front

What is the percent composition by mass of sulfur in a compound containing 9.0 g of aluminum, 28.0 g of sulfur, and 64.0 g of oxygen?

Back

28%.

Front

If a compound contains 24 g of carbon, 4 g of hydrogen, and 32 g of oxygen, what is the percent composition by mass of hydrogen?

Back

7%.

Front

What is the percent composition by mass of carbon in carbon dioxide (CO₂)?

Back

27.3%.

Front

What is the percent composition by mass of nitrogen in ammonia (NH₃)?

Back

82.2%.

Front

In the compound Li₃P, which element contributes more to the total mass?

Back

Phosphorus.

Front

What is the significance of knowing the percent composition by mass of a compound?

Back

It helps in understanding the chemical makeup of the compound and is useful in stoichiometric calculations.

Front

How does the atomic mass of an element affect its percent composition in a compound?

Back

Elements with higher atomic masses will contribute more to the total mass of the compound, affecting their percent composition.