Formulas and Percent by Mass

What is the empirical formula of a compound with 40% carbon, 6.7% hydrogen, and 53.3% oxygen?

• CH2O

• CH3O2

• C3H6O

• C2H4O2

How do you calculate the molecular formula from the empirical formula C2H5 and a molar mass of 58 g/mol?

• C5H12

• C2H5

• C3H8

• C4H10

If a compound contains 25% sodium, 35% chlorine, and 40% oxygen, what is its empirical formula?

• Na2Cl2O5

• Na2ClO4

• NaClO2

• NaClO3

Calculate the percent by mass of hydrogen in water (H2O).

• 33.33%

• 5.00%

• 20.00%

• 11.11%

A compound has an empirical formula of CH2 and a molar mass of 42 g/mol. What is its molecular formula?

• C4H8

• C3H6

• C1H2

• C2H4

What is the percent by mass of carbon in glucose (C6H12O6)?

• 50.00%

• 30.00%

• 40.00%

• 25.00%

Determine the empirical formula for a compound with 60% sulfur and 40% oxygen by mass.

• S2O

• S3O2

• SO4

• SO2

If a substance has a molecular formula of C4H10, what is its empirical formula?

• C3H8

• C4H10O

• C2H4

• C2H5

Calculate the percent by mass of nitrogen in ammonium nitrate (NH4NO3).

• 34.96%

• 25.00%

• 10.50%

• 50.00%

A compound has an empirical formula of C3H7 and a molar mass of 84 g/mol. What is its molecular formula?

• C5H12

• C7H16

• C4H10

• C6H14