Concept explainers
The following phase diagram shows part of the liquid/vapor phase-transition boundaries for pure ether and a solution of a nonvolatile solute in ether.
- (a) What is the approximate normal boiling point of pure ether?
- (b) What is the approximate molal concentration of the solute? [Kb for ether is 2.02 (°C ·kg)/mol.]
(a)
Interpretation:
The approximate normal boiling point of pure ether has to be determined
Answer to Problem 11.29CP
The approximate normal boiling point of pure ether is
Explanation of Solution
Let us consider the given phase diagrams
The given phase diagram shows part of the liquid and vapour phase-transition boundaries for pure ether and a solution of a non-volatile solute in ether.
Figure 1
The normal boiling point for ether is the temperature where the upper curve intersects so the approximate normal boiling point of pure ether is
(b)
Interpretation:
The approximate molal concentration of the solute has to be calculated.
Concept introduction:
- Elevation of boiling point:
The boiling point of the solution is increases when the solute is dissolved in the solvent is called Elevation of boiling point. It is one of the colligative Properties thus,
Answer to Problem 11.29CP
The approximate molal concentration of the solute is
Explanation of Solution
Given data,
The approximate molal concentration of the solute can be calculated as
The approximate molal concentration of the solute is
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Chapter 11 Solutions
General Chemistry: Atoms First
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