Chapter 2, Problem 2.119P

(a)

Interpretation Introduction

Interpretation:

The separation method used when a mixture of cooked pasta and boiling water in poured into a colander is to be identified.

Concept introduction:

The basic techniques of separation of mixture components are:

Filtration - The method of filtration is used to separate the components of a mixture whose particle sizes are different. Filtration is also used to separate solids from liquids using sieve plates.

Crystallization - The method of crystallization involves the separation of components from a mixture in which the components have a difference in their solubility in a particular solvent. On cooling down the solution, the desired component crystallizes out of the solution.

Distillation - This method involves heating and cooling the mixture with components having large differences in their boiling points. The component with lower boiling point vapourises first. The component vapours are cooled down and collected in separate containers.

Chromatography - This separation technique is based on the difference between the solubilities of the components of a mixture in mobile and stationary phases. The component having greater solubility in the mobile phase is separated and collected first whereas the component with greater solubility in the stationary phase is separated later.

(b)

Interpretation Introduction

Interpretation:

The separation method used when coloured impurities from raw sugar are removed to make refined sugar is to be identified.

Concept introduction:

The basic techniques of separation of mixture components are:

Filtration - The method of filtration is used to separate the components of a mixture whose particle sizes are different. Filtration is also used to separate solids from liquids using sieve plates.

Crystallization - The method of crystallization involves the separation of components from a mixture in which the components have a difference in their solubility in a particular solvent. On cooling down the solution, the desired component crystallizes out of the solution.

Distillation - This method involves heating and cooling the mixture with components having large differences in their boiling points. The component with lower boiling point vapourises first. The component vapours are cooled down and collected in separate containers.

Chromatography - This separation technique is based on the difference between the solubilities of the components of a mixture in mobile and stationary phases. The component having greater solubility in the mobile phase is separated and collected first whereas the component with greater solubility in the stationary phase is separated later.