Empirical and Molecular Formulas

Front

What is the definition of a molecular formula?

Back

A molecular formula shows the actual number of atoms of each element in a molecule, indicating the specific composition of the compound.

Front

What is the definition of an empirical formula?

Back

An empirical formula represents the simplest whole-number ratio of atoms of each element in a compound.

Front

How do you derive the empirical formula from a molecular formula?

Back

To derive the empirical formula, divide the subscripts in the molecular formula by their greatest common divisor.

Front

What is the empirical formula for C6H12O6?

Back

The empirical formula is C2H4O2.

Front

If a molecular formula is C18H34O3, how many hydrogen atoms are present?

Back

There are 34 hydrogen atoms.

Front

What is the empirical formula for Si2F6?

Back

The empirical formula is SiF3.

Front

Which two compounds have the same empirical formula: C2H4O2 and C6H12O6?

Back

Yes, both compounds have the same empirical formula, which is C2H4O2.

Front

What is the empirical formula of K2SO4?

Back

The empirical formula is K2SO4.

Front

How do you calculate the molecular formula from the empirical formula?

Back

To calculate the molecular formula, multiply the subscripts in the empirical formula by a whole number that gives the correct molecular mass.

Front

If the empirical formula is CF2 and the molecular formula mass is 192 g/mol, what is the molecular formula?

Back

The molecular formula is C4F8.