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 = (mass of sample in grams / molar mass) x Avogadro's number (6.022 x 10^23).

Front

What is the molar mass of helium (He)?

Back

The molar mass of helium is approximately 4.00 g/mol.

Front

How do you convert grams to moles?

Back

To convert grams to moles, use the formula: Moles = mass in grams / molar mass.

Front

What is the molar mass of copper (I) bromide (CuBr)?

Back

The molar mass of copper (I) bromide is approximately 143.5 g/mol.

Front

How do you calculate the mass of a substance from moles?

Back

To calculate mass from moles, use the formula: Mass = moles x molar mass.

Front

What is the volume of one mole of a gas at standard temperature and pressure (STP)?

Back

At STP, one mole of an ideal gas occupies 22.4 liters.

Front

How do you calculate the volume of a gas from the number of molecules?

Back

To calculate the volume of a gas from molecules, use the formula: Volume = (number of molecules / Avogadro's number) x 22.4 L.

Front

What is the density of water?

Back

The density of water is approximately 1 g/mL.

Front

How do you convert grams of water vapor to liters?

Back

To convert grams of water vapor to liters, use the formula: Volume (L) = mass (g) / density (g/mL).