Chapter 12.7, Problem 71PP

(a)

Interpretation Introduction

Interpretation: The molality of solution should be calculated.

Concept Introduction:The molality of solution is defined as number of moles of solute in 1 kg of solvent.

It is mathematically represented as follows:

  $m=\frac{n\left(\text{solute}\right)}{M\left(\text{solvent,kg}\right)}$

Here, n is number of moles of solute and M is mass of solvent.

From the mass, number of moles can be calculated as follows:

  $n=\frac{m}{M}$

Here, m is mass and M is molar mass.

(b)

Interpretation Introduction

Interpretation: The molality of solution should be calculated.

Concept Introduction:The molality of solution is defined as number of moles of solute in 1 kg of solvent.

It is mathematically represented as follows:

  $m=\frac{n\left(\text{solute}\right)}{M\left(\text{solvent,kg}\right)}$

Here, n is number of moles of solute and M is mass of solvent.

From the mass, number of moles can be calculated as follows:

  $n=\frac{m}{M}$

Here, m is mass and M is molar mass.