The Mole and Molar Mass

Front

What is the definition of a mole in chemistry?

Back

A mole is a unit of measurement in chemistry that represents 6.022 x 10²³ particles (atoms, molecules, ions, etc.) of a substance.

Front

How do you calculate the molar mass of a compound?

Back

To calculate the molar mass of a compound, sum the atomic masses of all the atoms in its chemical formula, using the periodic table.

Front

What is the molar mass of C8H18 (octane)?

Back

The molar mass of C8H18 is approximately 114.22 g/mol.

Front

How do you convert moles to grams?

Back

To convert moles to grams, multiply the number of moles by the molar mass of the substance (grams per mole).

Front

How do you convert grams to moles?

Back

To convert grams to moles, divide the mass in grams by the molar mass of the substance (grams per mole).

Front

What is the relationship between moles and molecules?

Back

1 mole of any substance contains 6.022 x 10²³ molecules of that substance.

Front

What is the mass of 1 mole of oxygen gas (O2)?

Back

The molar mass of O2 is approximately 32 g/mol, so 1 mole of O2 has a mass of 32 grams.

Front

How many moles are in 44 grams of carbon dioxide (CO2)?

Back

To find the number of moles in 44 grams of CO2, divide 44 g by its molar mass (approximately 44 g/mol), resulting in 1 mole.

Front

What is Avogadro's number?

Back

Avogadro's number is 6.022 x 10²³, which is the number of particles in one mole of a substance.

Front

What is the mass of 2.50 moles of oxygen gas (O2)?

Back

The mass of 2.50 moles of O2 is 2.50 moles x 32 g/mol = 80 grams.