Molecular Formula Calculation Quiz

What is the relationship between molecular and empirical formulas?

• Empirical formula is a whole number multiple of the molecular formula.

• Molecular formula is a fraction of the empirical formula.

• Empirical formula is a fraction of the molecular formula.

• Molecular formula is a whole number multiple of the empirical formula.

How is the molar mass of a compound related to its empirical formula molar mass?

• It is always less than the empirical formula molar mass.

• It is unrelated to the empirical formula molar mass.

• It is a whole number multiple of the empirical formula molar mass.

• It is equal to the empirical formula molar mass.

What is the value of n if the molar mass of a compound is 78.11 g/mol and its empirical formula is CH?

• 4

• 6

• 3

• 5

If the empirical formula is CH and n is found to be 6, what is the molecular formula?

• C2H2

• C3H3

• CH

• C6H6

What is the empirical formula molar mass of CH?

• 12.01 g/mol

• 14.018 g/mol

• 1.008 g/mol

• 13.018 g/mol

In the example with NH3, what is the molar mass of the compound?

• 1.008 g/mol

• 28.02 g/mol

• 14.01 g/mol

• 33.7 g/mol

What is the value of n for the compound with empirical formula NH3 and molar mass 33.7 g/mol?

• 1

• 2

• 3

• 4

If n is 2 for the empirical formula NH3, what is the molecular formula?

• NH3

• N3H9

• NH6

• N2H6

What is the empirical formula molar mass of NH3?

• 14.01 g/mol

• 17.034 g/mol

• 1.008 g/mol

• 18.038 g/mol

What must be known to calculate the molecular formula of a compound?

• Neither the empirical formula nor molar mass

• Both the empirical formula and molar mass

• Only the molar mass

• Only the empirical formula