Unit 1 AOS 2 Empirical and molecular Formula Quiz (7A)

A compound contains 40% sulfur and 60% oxygen by mass. What is the empirical formula of the compound? Assume the molar mass of sulfur (S) is 32 g/mol and oxygen (O) is 16 g/mol.

• SO

• 92.3%

• 84.1%

• 77.4%

• 85.7%

A compound is analyzed and found to contain 27.29% potassium, 1.07% hydrogen, 14.48% carbon, and 57.16% oxygen. What is the empirical formula of this compound? Assume atomic masses: K = 39 g/mol, H = 1 g/mol, C = 12 g/mol, O = 16 g/mol.

Tags

NGSS.HS-PS1-2

NGSS.HS-PS1-7

• 0.5 moles

• 1 mole

• 1.11 moles

• 5.56 moles

• 35%

• 28%

• 17.5%

• 22.2%

• 5

• 7

• 10

• 12

What is the empirical formula for a compound if it contains 70% iron (Fe) and 30% oxygen (O) by mass? Assume atomic masses: Fe = 56 g/mol, O = 16 g/mol.

• FeO