Chemical Quantities Review

Front

What is percent composition?

Back

Percent composition is the percentage by mass of each element in a compound.

Front

How do you calculate the percent composition of an element in a compound?

Back

Percent composition = (mass of element in 1 mole of compound / molar mass of compound) x 100%.

Front

What is the molar mass of a substance?

Back

Molar mass is the mass of one mole of a substance, typically expressed in grams per mole (g/mol).

Front

What are the units of molar mass?

Back

grams/mole (g/mol).

Front

What is an empirical formula?

Back

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

Front

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

Back

Divide the subscripts in the molecular formula by their greatest common divisor.

Front

What is a molecular formula?

Back

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

Front

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

Back

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

Front

What is the empirical formula of C3H6?

Back

CH2.

Front

What is the molecular formula if the empirical formula is CH2O and the molar mass is 180.18 g/mol?

Back

C6H12O6.