# Why is there a need to have both molarity and molality?

Apr 17, 2017

Why? Because $\text{molarity}$ can be dependent on temperature......

#### Explanation:

....and depending on the solvent, its concentration over a temperature range may vary.

On the other hand, $\text{molality}$ depends solely on terms that do not vary with temperature: $\text{moles of solute"/"kilograms of solvent}$. At moderate concentrations there is only marginal difference between the terms.