Percent Composition Calculations
Chemistry ⇒ Stoichiometry and Chemical Calculations
Percent Composition Calculations starts at 9 and continues till grade 12.
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See sample questions for grade 10
A 10 g sample of a compound contains 4 g of nitrogen. What is the percent composition of nitrogen in the compound?
A 50 g sample of a compound contains 20 g of element X. What is the percent composition of X?
A compound contains 24 g of magnesium and 16 g of oxygen. What is the percent composition of magnesium?
A compound is found to contain 70% iron and 30% oxygen by mass. What is the empirical formula? (Atomic masses: Fe = 56, O = 16)
A 10 g sample of a compound contains 4 g of nitrogen. What is the percent composition of nitrogen in the compound?
A 50 g sample of a compound contains 20 g of element X. What is the percent composition of X?
A compound contains 24 g of magnesium and 16 g of oxygen. What is the percent composition of magnesium?
A compound is found to contain 70% iron and 30% oxygen by mass. What is the empirical formula? (Atomic masses: Fe = 56, O = 16)
Which element has the highest percent composition in NaCl? (Atomic masses: Na = 23, Cl = 35.5) (1) Sodium (2) Chlorine (3) Both are equal (4) Cannot be determined
Which of the following best describes the steps to calculate percent composition? (1) Find the molar mass of the compound. (2) Divide the mass of each element by the molar mass. (3) Multiply by 100. (4) Add the atomic numbers of each element.
Which of the following compounds has the highest percent by mass of oxygen? (1) H2O (2) CO2 (3) SO2 (4) Na2O
Which of the following compounds has the lowest percent by mass of hydrogen? (1) H2O (2) CH4 (3) NH3 (4) C2H6
Fill in the blank: The percent composition of calcium in CaCl2 is __________%. (Atomic masses: Ca = 40, Cl = 35.5)
Fill in the blank: The percent composition of carbon in CO2 is __________%. (Atomic masses: C = 12, O = 16)
Fill in the blank: The percent composition of chlorine in KCl is __________%. (Atomic masses: K = 39, Cl = 35.5)
Fill in the blank: The percent composition of nitrogen in NH3 is __________%. (Atomic masses: N = 14, H = 1)
True or False: Percent composition can be used to determine the empirical formula of a compound.
True or False: Percent composition can help identify an unknown compound.
True or False: The percent composition of a compound depends on the sample size.
True or False: The percent composition of a hydrate includes the water of crystallization.
