Chemistry: Molarity, Molality, Mole Fraction, and Percent by Mass Calculations

Molarity (M)

amount of solute (in mol)/ volume of solution (in L)

Molality (m)

amount of solute (in mol)/ mass of solvent (in kg)

Mole fraction

amount of solute (in mol)/ total amount of solute and solvent (in mol)

Percent by mass

mole fraction * 100

If given molarity (M)

assume 1 L solution.

If given molality (m)

assume 1 kg solvent.

If given % by mass

assume 100 g solution.

If given mol fraction

assume 1 total mole of solution.

Solution Composition

solvent + solute = solution.