Question

How do you find the freezing point and boiling point ?

Answer 1

Freezing and boiling point-

As we know the freezing point of water is $0°\mathrm{C}$ and the boiling point of water is $100°\mathrm{C}$. Freezing and boiling point changes as follows; when the matter is dissolved in a liquid, freezing point becomes lower and the boiling point becomes higher.

Calculating the change in freezing point-

Step 1- We have to observe the freezing point of the liquid by which we can calculate the new freezing point.

Freezing point $=$(Old freezing point$-{\mathrm{K}}_{\mathrm{f}}$) $\times$ Molality, where ${\mathrm{K}}_{\mathrm{f}}=$Freezing point depression constant

Step-2 We have to observe the boiling point of the liquid by which we can calculate the new boiling point.

Boiling point $=$(Old boiling point $+{\mathrm{K}}_{\mathrm{b}}$) $\times$Molality, where ${\mathrm{K}}_{\mathrm{b}}=$Boiling point elevation constant

The above points clearly explain the evaluation of freezing point and boiling point.