Molarity, Molality, & Normality

Molarity (M) and Molality (m)

These are both measures of concentration

Molarity (M)

The moles of a solute per liters of a solution

Molality (m)

The moles of a solute per kilograms of a solvent

M = moles solute / liters solution

Equation for Molarity

m = moles solute / kilograms solvent

Equation for Molality

volume (in liters)

Molarity is ratio of moles to:

mass (in kilograms)

Molality is ratio of moles to:

Molality

aka "molal concentration"

Molarity

aka "molar concentration"

Molarity

most common concentration unit in chemistry

Molality molal concentration

one of the concentration units which is one molal solution contains one mole per 1000g of solvent (mol/kg).

Molality molal concentration

It does not change with temperature.

Normality

is a measure of concentration equal to the gram equivalent weight per liter of solution.

Gram equivalent weight

is the measure of the reactive capacity of a molecule

To determine the normality of the solution

Role of solute in normality

Normality

is also known as the equivalent concentration of a solution.