Empirical and Molecular Formulas

Front

What is an empirical formula?

Back

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

Front

What is a molecular formula?

Back

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

Front

How do you determine the empirical formula from percent composition?

Back

Convert the percentages to grams, then to moles, and find the simplest whole-number ratio.

Front

What does a subscript in a chemical formula indicate?

Back

A subscript indicates the number of atoms of the element in the molecule.

Front

Given the molecular formula C6H12O6, what is the empirical formula?

Back

The empirical formula is CH2O.

Front

How do you convert an empirical formula to a molecular formula?

Back

Multiply the subscripts in the empirical formula by a whole number to match the molecular mass.

Front

What is the empirical formula of a compound with 40% carbon and 60% oxygen by mass?

Back

The empirical formula is CO.

Front

If the empirical formula is NH2 and the molecular mass is 32 g/mol, what is the molecular formula?

Back

The molecular formula is N2H4.

Front

What is the significance of the molecular formula?

Back

The molecular formula provides information about the actual number of atoms in a molecule, which is important for understanding its chemical properties.

Front

How many hydrogen atoms are in C18H34O3?

Back

There are 34 hydrogen atoms.