# Are the concentrations of molar or normal solutions affected by temperature?

Apr 15, 2017

The concentrations of both normal and molar solutions are affected by temperature.

#### Explanation:

Normality is defined as the number of equivalents of solute in a litre of solution.

color(blue)(|bar(ul(color(white)(a/a)"Normality" = "equivalents"/"litres"color(white)(a/a)|)))" "

Molarity is defined as the number of moles of solute in a litre of solution.

color(blue)(|bar(ul(color(white)(a/a)"Molarity" = "moles"/"litres"color(white)(a/a)|)))" "

However, the volume of a liquid usually increases as the temperature increases.

Since volume is in the denominator of the expressions for both normality and molarity, these values will change when the temperature changes.

For example, if you prepare 1 L of a solution with water at 15 °C but don't use it until its temperature has increased to 25 °C, its volume will have increased from 1000 mL to 1002 mL.

A solution with a concentration of 1.000 mol/L at 15 °C will be only 0.0998 mol/L at 25 °C.