Chapter 11, Problem 11.130CHP

Interpretation Introduction

Interpretation:

The molar mass of the given unknown organic compound has to be calculated.

Concept introduction:

• Depression in freezing point:

  The freezing point the solution is decreases when the solute is dissolved in the solvent is called depression in freezing point.  It is one of the colligative Properties thus,

$\begin{array}{l}\text{ΔT}\text{=}{\text{iK}}_{\text{f}}{\text{m}}_{\text{solute}}\mathrm{......}(2)\\ \text{ΔT is boiling-point elevation}\\ {\text{K}}_{\text{f}}\text{is}\text{molal freezing-point depression constant}\\ \text{m}\text{is }\text{molality of the solute}\\ \text{i}\text{is}\text{the}\text{van't Hoff factor}\end{array}$

Osmotic pressure

The additional pressure that has to be given to solution in order to stop osmosis is called as osmotic pressure.  Osmosis is the run of solvent into a solution by means of semipermeable membrane.

Osmotic pressure can be calculated by the equation,

$\Pi \text{=}\text{MRT}$

$\begin{array}{l}\Pi \text{=Osmotic}\text{pressure}\\ \text{M=}\text{Molarity}\text{of}\text{solution}\\ \text{R=Gas}\text{law}\text{constant}\\ \text{T=Temperature}\end{array}$