HC Quiz A: Percent Composition, EF and MF

What is the percent composition of benzene, C₆H₆? Show work.

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What is the empirical formula if you have 88.80% copper and 11.20% oxygen? Show work.

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What percent of Zn₃(PO₄)₂ is zinc? Show work.

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• 33.15%

• 16.04%

• 50.80%

• 19.68%

If 45.0 g of Mg react with 19.5 g of oxygen, what is the % of magnesium in the resulting compound? Show work.

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• 69.8%

• 30.2%

• 43.3%

• 12.9%

What is the molecular formula for a compound with the empirical formula: K₂SO₄ and a molecular mass of 696g. Show work.

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Given the following: 42.07% Na, 18.89% P, and 39.04% O, determine the empirical formula and name formula. Show work

Analysis of ibuprofen yields a molar mass of 206g/mol, and the following composition: 75.7%C, 8.80%H, and 15.5% O. What is the molecular formula of ibuprofen? Show work.