Chapter 6.8, Problem 6.12QC

Interpretation Introduction

Interpretation:

The boiling point of a solution should be determined.

Concept introduction:

The concepts which are used here are as follows:

Boiling point: The temperature at which both the atmospheric pressure and vapor pressure becomes equal.

• Elevation in boiling point: The boiling point of a solution containing non volatile solute is greater than pure solvent, that increase in boiling point of solution in comparison to pure solvent is called elevation in boiling point. It is given by the following expression

$\Delta T_b=T_b-T^0{}_b$

• Molal elevation constant: It is defined as the elevation in boiling point when the molality of the solution is unity. It is denoted by K_b .
• Solute: The component which is present in less amount in solution.
• Solvent: The component which is present in greater amount in solution.
• The relation between elevation in boiling point, molal elevation constant, molar mass of solute and solvent is as follows:

$\begin{array}{l}\Delta T_b=\frac{1000\times K_b\times W_b}{W_{\text{a}}\times M_b}\\ W\text{H}\text{e}r\text{e}{W}_{\text{a}}=massofs\text{O}\text{l}v\text{e}nt\\ W_b=massofsolute\\ M_b=m\text{O}\text{l}\text{a}rmassofsolute\end{array}$.