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 9

A 100 g sample of a compound contains 40 g of sulfur and 60 g of oxygen. What is the percent composition of oxygen?

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

A 50 g sample of a compound contains 10 g of hydrogen. What is the percent composition of hydrogen?

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 percent composition of 52.2% carbon, 13.0% hydrogen, and 34.8% oxygen. What is the empirical formula?

A sample of NaCl has a mass of 58.5 g. What is the percent by mass of sodium in NaCl? (Na = 23, Cl = 35.5)

Calculate the percent composition of carbon in \mathrm{C_6H_{12}O_6}. (C = 12, H = 1, O = 16)

Calculate the percent composition of chlorine in \mathrm{CaCl_2}. (Ca = 40, Cl = 35.5)

Calculate the percent composition of hydrogen in \mathrm{H_2O}. (Atomic masses: H = 1, O = 16)

Calculate the percent composition of magnesium in \mathrm{MgCl_2}. (Mg = 24, Cl = 35.5)

Calculate the percent composition of nitrogen in \mathrm{NH_3}. (N = 14, H = 1)

Calculate the percent composition of oxygen in \mathrm{Al_2O_3}. (Al = 27, O = 16)

Calculate the percent composition of potassium in \mathrm{KNO_3}. (K = 39, N = 14, O = 16)

Calculate the percent composition of sulfur in \mathrm{H_2SO_4}. (H = 1, S = 32, O = 16)

If a compound has a percent composition of 40% carbon, 6.7% hydrogen, and 53.3% oxygen, what is its empirical formula?

What is meant by percent composition in chemistry?

Which element has the highest percent composition in \mathrm{H_2SO_4}? (H = 1, S = 32, O = 16)

A 120 g sample of a compound contains 24 g of hydrogen and the rest is carbon. What is the percent composition of carbon in the compound?

A compound has the formula \mathrm{X_2Y_3}. If the molar mass of X is 10 g/mol and Y is 20 g/mol, what is the percent composition of Y in the compound?

A hydrate of magnesium sulfate has the formula \mathrm{MgSO_4 \cdot 7H_2O}. Calculate the percent by mass of water in the hydrate. (Mg = 24, S = 32, O = 16, H = 1)