Percent Composition by Mass

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 percent composition by mass of an element in a compound?

Back

Percent composition = (mass of element / total mass of compound) x 100.

Front

What is the percent composition by mass of hydrogen in a compound containing 24g of carbon, 4g of hydrogen, and 32g of oxygen?

Back

7%.

Front

If a compound has a total mass of 180 grams and is composed of 40% carbon, what is the mass of carbon in the compound?

Back

72 g.

Front

What is the percent composition by mass of oxygen in water (H2O)?

Back

89%.

Front

How do you find the mass of an element from its percent composition?

Back

Mass of element = (percent composition / 100) x total mass of compound.

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 sample contains 40g of calcium, 12g of carbon, and 48g of oxygen, what is the percent composition by mass of calcium?

Back

40%.

Front

What is the total mass of a compound if it contains 40% carbon and the mass of carbon is 72g?

Back

180 g.

Front

What is the percent composition by mass of oxygen in a compound with 32g of oxygen and a total mass of 100g?

Back

32%.