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Lesson Worksheet: Percentage Composition Chemistry • 10th Grade
In this worksheet, we will practice calculating the percentage composition of a substance using chemical formulas or the masses of constituent elements.
A compound Y contains one atom of element X per formula unit. The relative formula mass of Y is known. What is the formula for expressing the mass of X in compound Y as a percentage of the total mass?
- A =
- B =
- C =
- D =
- E =
A sample of a compound composed of only elements and has a mass of 50 g. After elemental analysis, it is shown that the sample contains 45 g of . To the nearest percentage unit, what is the mass of in the sample as a percentage of the total mass?
A sample of a compound has a mass of 80 g and is composed entirely of elements and . Elemental analysis shows that the sample contains 20 g of . To the nearest percentage point, what is the mass of in the sample as a percentage of the total mass?