Drying

Drying is the process of removing the liquid from solid substance by heating and the unit operation in which the mass transferred. Further it is the process of synthesizing and isolating an organic compound frequently effects in an organic compound or solution contaminated with traces of water. For example, in aqueous extractions some water will be transferred into the organic phase because of the partial miscibility of the organic phase and water. And there are several reactions themselves which are performed in an aqueous solution. This water should be removed before the desired compound can be properly characterized.

The two common methods of drying

There are two methods commonly used for drying solutions such as saturated aqueous sodium chloride and solid drying agents. The bulk of the water can be frequently removed by shaking or washing the layer with saturated aqueous sodium chloride. The salt water works to drag the water from the organic layer to the water layer. It is due to the concentrated salt solution wants to become more dilute and because salts have a stronger attraction to water than to organic solvents. And sometimes a saturated aqueous of sodium chloride is called brine.

Drying agents

The last traces of water are removed by treating the organic solution with a drying agent. A drying agent is an inorganic salt that is readily takes up water to become hydrated. Those salts are employed routinely in the organic chemistry teaching labs these days. Calcium chloride has more capacity and used for hydrocarbons whereas calcium sulfate is also an agent which is low in capacity relatively faster and generally useful. And magnesium sulfate is also high in capacity and faster but they are not used for acid sensitive compounds.

Potassium carbonate which possesses medium capacity and speed is also not meant for acidic compounds and sodium sulfate is high in capacity and slow but generally useful. Magnesium sulfate is a fine powder and the rest above mentioned are of a larger particle size. Calcium chloride, magnesium sulfate and sodium are widely used drying agents than the rest of them.

Qualities of different drying agent

Every drying agent is slightly different in appearance when they are clumped and practice makes better judging them as inorganic salt wet or dry. This is because there is no prescription about how much drying agent required to be added. The amount depends on the amount of water in the solvent solution that is made drying and it differs with each experiment.

Questions:

• Define drying.
• What are the uses of drying?