Chapter 13.7, Problem 13.11PSP

Interpretation Introduction

Interpretation:

Addition of $\text{1}\text{.20 kg}$ ethylene glycol would be sufficient or not to prevent the solution from freezing if the temperature drops to ${\text{-25}}^{\text{o}}\text{C}$ has to be shown using calculation.

Concept introduction

Freezing point is the temperature at which liquid turns into solid.

The Freezing point depression${\text{(ΔT}}_{\text{f}}\text{)}$ is indicated as ${\text{ΔT}}_{\text{f}}{\text{= K}}_{\text{f}}\text{m}$

Where,

${\text{ΔT}}_{\text{f}}-$ Change in freezing point

${\text{K}}_{\text{f}}-$ Molal freezing point constant

$m-$ Molality of the solution

From given mass of substance moles could be calculated by using the following formula,

  $\text{Moles}\text{of}\text{substance }\text{= }\frac{\text{Given}\text{mass}\text{of}\text{substance}}{\text{Molecular}\text{mass}}$

Molality: It is a measure of the concentration of a solute in a solution in terms of amount of substance in the amount of mass of solvent.

  $\text{m}\text{=}\frac{\text{mol}}{\text{kg}}$

Where, m is molality; mole is moles of solute and kg is mass of solvent.