Question

each of the identical volumetric flasks contains the same solution at two different temperatures. what changes for the solution with temperature? molarity molality both molarity and molality neither molarity or molality

Explanation:

Molarity is defined as moles of solute per liter of solution ($M=\frac{n}{V}$). Volume of the solution changes with temperature due to thermal expansion or contraction. Molality is defined as moles of solute per kilogram of solvent ($m = \frac{n}{m_{solvent}}$), and mass of the solvent does not change with temperature. So only molarity changes with temperature.

Answer:

A. molarity