Moles, Molarity, and Molar Mass

Front

What is a mole?

Back

A mole is a unit of measurement in chemistry that represents 6.022 x 10^23 particles (atoms, molecules, ions, etc.).

Front

What is molarity?

Back

Molarity is a measure of concentration, defined as the number of moles of solute per liter of solution (mol/L).

Front

How do you calculate molarity?

Back

Molarity (M) = moles of solute / liters of solution.

Front

What is the molar mass of a substance?

Back

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

Front

How do you find the molar mass of NaCl?

Back

Add the atomic masses of sodium (Na, 23 g/mol) and chlorine (Cl, 35.5 g/mol) to get 58.5 g/mol.

Front

What is the molarity of a solution containing 2.6 moles of NaCl in 500.0 mL?

Back

5.2 M (calculated as 2.6 moles / 0.5 L).

Front

What is the mass of one mole of aluminum?

Back

27 g.

Front

What is the molarity of 1 mole of Ba⁺ in 2 L of water?

Back

0.5 M (calculated as 1 mole / 2 L).

Front

What units are used to express molarity?

Back

Molarity is expressed in moles per liter (mol/L).

Front

What is the relationship between moles and molar mass?

Back

Moles = mass (g) / molar mass (g/mol).