Chemical Formulas and Molecular Composition Quiz

Test your knowledge of molecular chemistry with questions on molecular and empirical formulas, percent composition, and molar mass.

Practice Learn Test

Which of the following represents the molecular formula for water?

H2O2

H2O

HHO

What is the molecular formula for methane?

CH4

CO2

H2O

NH3

What is the molecular formula for sulfuric acid?

SO3

H2SO4

HSO4

SO2

How many oxygen atoms are there in one molecule of carbon dioxide (CO2)?

What is the empirical formula for a compound composed of 12.0 g of carbon and 4.0 g of hydrogen?

CH2

C2H

C2H4

Calculate the percent composition of sodium chloride (NaCl).

Na = 22.99%, Cl = 35.45%

Na = 35.45%, Cl = 22.99%

Na = 58.44%, Cl = 41.56%

Na = 41.56%, Cl = 58.44%

What is the empirical formula for a compound composed of 30.0% phosphorus and 70.0% oxygen by mass?

PO2

P2O5

P4O10

P3O7

Calculate the percent composition of glucose (C6H12O6).

C = 40.0%, H = 6.67%, O = 53.3%

C = 40.0%, H = 53.3%, O = 6.67%

C = 53.3%, H = 40.0%, O = 6.67%

C = 6.67%, H = 40.0%, O = 53.3%

What is the molar mass of magnesium sulfate (MgSO4)?

120.37 g/mol

138.21 g/mol

142.44 g/mol

156.38 g/mol

#10

What is the molar mass of calcium carbonate (CaCO3)?

100.09 g/mol

116.16 g/mol

147.04 g/mol

173.12 g/mol

#11

What is the molar mass of sulfuric acid (H2SO4)?

96.06 g/mol

98.08 g/mol

100.09 g/mol

102.11 g/mol

#12

What is the molar mass of ammonium phosphate ((NH4)3PO4)?

145.09 g/mol

149.09 g/mol

163.06 g/mol

169.09 g/mol