1.3: Elemental Composition of Pure Substances

Multiple Choice

Which of the following is considered an empirical formula?

• S₂O₄

• C₆H₁₂O₆
• H₂O
• C₂H₄

Multiple Choice

A compound consists of 72.2% magnesium(Mg) and 27.8% nitrogen(N) by mass. What is the empirical formula?

• Mg₄N₃
• MgN₂
• Mg₃N₂ 
• MgN

Labelling

MATCH THE EMPIRICAL AND MOLECULAR FORMULAS.

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Multiple Choice

Glycerol has a molar mass of 92.09g/mol. Its percent composition is: 39.12% C, 8.75% H, and 51.12% O. What is the molecular formula for glycerol?

• C₂H₃O₂
• CH₂O
• C₂H₄O₂
• C₃H₈O₃