Percent Composition Calculations

Chemistry ⇒ Stoichiometry and Chemical Calculations

Percent Composition Calculations starts at 9 and continues till grade 12. QuestionsToday has an evolving set of questions to continuously challenge students so that their knowledge grows in Percent Composition Calculations. How you perform is determined by your score and the time you take. When you play a quiz, your answers are evaluated in concept instead of actual words and definitions used.

See sample questions for grade 12

A 10.0 g sample of a compound contains 2.0 g of hydrogen. What is the percent composition of hydrogen in the compound?

A 200 g sample of a compound contains 80 g of carbon. What is the percent composition of carbon?

A 25.0 g sample of a compound contains 5.0 g of nitrogen. What is the percent composition of nitrogen?

A 50.0 g sample of a compound contains 20.0 g of oxygen. What is the percent composition of oxygen?

A compound contains 12.0 g of carbon, 2.0 g of hydrogen, and 16.0 g of oxygen. What is the percent composition of hydrogen?

A compound contains 14.0 g of nitrogen and 32.0 g of oxygen. What is the percent composition of nitrogen?

A compound contains 24.3% magnesium, 27.0% sulfur, and 48.7% oxygen by mass. What is the empirical formula of the compound?

A compound has a molar mass of 100 g/mol and contains 20 g of hydrogen per mole. What is the percent composition of hydrogen?

A compound has a molar mass of 180 g/mol and contains 72 g of carbon per mole. What is the percent composition of carbon?

A sample of NaCl weighs 58.44 g. How many grams of sodium are present in the sample?

Calculate the percent composition of carbon in C₆H₁₂O₆.

Calculate the percent composition of chlorine in CaCl₂.

Calculate the percent composition of nitrogen in NH₄NO₃.

Calculate the percent composition of phosphorus in P₂O₅.

Calculate the percent composition of potassium in KNO₃.

Calculate the percent composition of sulfur in H₂SO₄.

If a compound is 40% sulfur and 60% oxygen by mass, what is the simplest formula for the compound?

What is the percent composition by mass of hydrogen in H₂O?

A 5.00 g sample of a compound contains 1.20 g of element X and 3.80 g of element Y. What is the percent composition of element X?

A compound contains 54.5% C, 9.1% H, and 36.4% O by mass. What is its empirical formula?