Percent Composition, Empirical and Molecular Formula

What is the empirical formula if you have 81.82% carbon and 18.18% hydrogen?

• C₃H₈

• CH₄

• C₂H₂

• C₄H₁₀

An 8 g sample of a compound is found to be 3.766 g aluminum & 4.234 g 0xygen. What is it's empirical formula?

• Al₂O₃

• AlO₂

• Al₂O

• Al₃O₂

Tags

NGSS.HS-PS1-7

What is the molecular formula if the empirical formula is C₂H₅ and the molecular molar mass is 58.14 g/mol?

• C₂H₅

• C₄H₁₀

• C₁H_2.5

• C₄H₈

A compound has a molar mass of 92.09g/mol. Its percent composition is: 39.12% C, 8.76% H, and 52.12% O. What is the molecular formula?

• C₂H₃O₂

• CH₂O

• C₂H₄O₂

• C₃H₈O₃

Tags

NGSS.HS-PS1-1

What percent of Zn₃(PO₄)₂ is zinc?

• 33.15%

• 16.04%

• 50.80%

• 19.68%

What is the percent composition of a compound that contains 40.8 g carbon and 54.4 g oxygen?

• 42.9 %; 57.1% oxygen

• 52.9 %; 57.1% oxygen

• 42.9 %; 45.23% oxygen

• 55.9 %; 99.1% oxygen

Tags

NGSS.HS-PS1-7

What is the percentage of iron in iron(III)oxide?

• 30%

• 70%

• 40%

• 60%

If 45.0 g of Mg react with 19.5 g of oxygen, what is the % ofmagnesium in the resulting compound?

• 69.8%

• 30.2%

• 43.3%

• 12.9%

Tags

NGSS.HS-PS1-7

Which of the following is considered an empirical formula?

• CH₃COOH

• C₆H₁₂O₆

• H₂O

What is the empirical formula if you have 81.82% carbon and 18.18% hydrogen?

• C3H8

• CH4

• C2H2

• C4H10