Chapter 10, Problem 130IP

Interpretation Introduction

Interpretation: The molality of normal Creatinine solution and osmotic pressure at $\text{25°C}$ has to be calculated.

Concept Introduction:

Molality of a solution also called as molal concentration can be defined as the mass of solute in grams to the mass of the solvent in kilograms. It can be given by the equation,

$\text{Molality(mol}{\text{kg}}^{\text{-1}}\text{)=}\frac{\text{Mass}\text{of}\text{solue(in}\text{g)}}{\text{Mass}\text{of}\text{solvent(in}\text{kg)}}$

When a semipermeable membrane, separates a solution and pure solvent. The solvent molecules are passed through the semi permeable membrane. There is gradual increase in the volume of solution with a decrease in volume of the solvent with respect to time. The flow of solvent through a semipermeable membrane into the solution is called as osmosis. By the time system reaches equilibrium, the changes in the liquid level stops. There is a higher hydrostatic pressure on the solution than compared to that of the pure solvent because there is variation in the liquid levels at this point. The excess pressure on the solution is called osmotic pressure.

The osmotic pressure of solution is calculated by using,

$\text{Π=MRT}$

Here,

$\text{Π=}\text{osmotic}\text{pressure(in atm)}$

$\text{M=molarity}\text{of}\text{solution(in}\text{M)}$

$\text{R=}\text{Gas}\text{constant}$

$\text{T=Temperature(in}\text{K)}$