12/4/24 Empirical and Molecular Formulas IP

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

How do you determine the empirical formula from percent composition?

Back

Convert the percentages to grams, then to moles, and simplify the mole ratio to the smallest whole numbers.

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 is the empirical formula related to the molecular formula?

Back

The molecular formula is a whole-number multiple of the empirical formula.

Front

Given the molecular formula C6H12, what is the empirical formula?

Back

The empirical formula is C3H6.

Front

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

Back

The empirical formula is CO.

Front

How many hydrogen atoms are in the molecular formula C18H34O3?

Back

There are 34 hydrogen atoms.

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.

Front

What is the empirical formula for Si2F6?

Back

The empirical formula is SiF3.

Front

How do you find the number of atoms in a molecular formula?

Back

Count the subscripts in the molecular formula; if no subscript is present, it is assumed to be 1.