Mole Calculations

Front

What is a mole in chemistry?

Back

A mole is a unit of measurement used to express amounts of a chemical substance, defined as exactly 6.022 x 10^23 particles (atoms, molecules, ions, etc.).

Front

How do you calculate the number of atoms in a sample?

Back

To calculate the number of atoms, use the formula: Number of atoms = (moles of substance) x (Avogadro's number, 6.022 x 10^23).

Front

What is Avogadro's number?

Back

Avogadro's number is 6.022 x 10^23, which is the number of particles in one mole of a substance.

Front

How do you convert grams to moles?

Back

To convert grams to moles, use the formula: Moles = mass (g) / molar mass (g/mol).

Front

What is the molar mass of a compound?

Back

The molar mass of a compound is the mass of one mole of that compound, calculated by summing the atomic masses of all atoms in its formula.

Front

Calculate the mass of 1 mole of water (H2O).

Back

The molar mass of water is approximately 18 g/mol, so 1 mole of water has a mass of 18 grams.

Front

How do you find the mass of a sample given the number of moles?

Back

To find the mass of a sample, use the formula: Mass (g) = moles x molar mass (g/mol).

Front

What is the total mass of 0.5 moles of CO2?

Back

The molar mass of CO2 is approximately 44 g/mol, so the total mass is 0.5 moles x 44 g/mol = 22 grams.

Front

How many moles are in 12 grams of carbon (C)?

Back

The molar mass of carbon is approximately 12 g/mol, so 12 grams of carbon is 1 mole.

Front

What is the relationship between moles and particles?

Back

1 mole of any substance contains Avogadro's number (6.022 x 10^23) of particles.