Question

how relate molality and molarity

Answer 1

Molarity and molality are both measures of concentration of solutions. Molarity is the ratio of moles to volume of the solution while molality is the ratio of moles to the mass of the solution. Most of the time, it doesn't matter which unit of concentration you use. However, molality is preferred when a solution will undergo temperature changes because altering temperature affects volume (thus changing the concentration if molarity is used).

Molarity, also known as molar concentration, is the number ofmoles of a substance per liter of solution. Solutions labeled with the molar concentration are denoted with a capital M. A 1.0 M solution contains 1 mole of solute per liter of solution.

Molality is the number of moles of solute per kilogram of solvent. It is important the mass of solvent is used and not the mass of the solution. Solutions labeled with molal concentration are denoted with a lower case m. A 1.0 m solution contains 1 mole of solute per kilogram of solvent.

Answer 2

Answer:

Molarity (M) is defined as the number of moles of solute per liter of solution.

Molality (m) is defined as the number of moles of solute per kilogram of solvent.