Question

How does molarity change with temperature ?

Answer 1

Now the moles of solute are a constant. The volume of solution MAY change substantially with increasing or decreasing temperature. In some calculations molality is used in preference, which is defined by the quotient....
$\text{molality}=\frac{\text{moles of solute}}{\text{kilograms of solvent}}$
........this is temperature independent, and at lower concentrations,
$\text{molarity}\equiv \text{molality}$