Purifying Organic Products Flashcards
What happens when preparing samples of organic liquids?
Water may be obtained along with the product, resulting in two liquid layers: the organic layer and the aqueous layer.
How can you identify the organic layer in a mixture?
Add some water to the mixture; the layer that increases in volume is the aqueous layer.
What is the first step in separating the organic and aqueous layers?
Ensure that the tap of the separating funnel is closed.
What should you do after pouring the mixture into the separating funnel?
Place a stopper in the top of the funnel and invert to mix the contents.
What should you do after allowing the layers to settle in the separating funnel?
Add some water to see which layer increases in volume; this is the aqueous layer.
What is the purpose of placing a conical flask under the separating funnel?
To collect the organic layer after removing the stopper and opening the tap.
What should be done with the two conical flasks after separation?
Label the flasks to avoid mixing them up.
How can acid impurities be removed from an impure product?
By adding aqueous sodium carbonate and shaking the mixture in the separating funnel.
What gas is released when acid reacts with sodium carbonate?
Carbon dioxide gas.
What is the purpose of a drying agent?
To remove traces of water from the organic liquid.
What is an example of a common drying agent?
Anhydrous calcium chloride.
What is the procedure for drying an organic liquid?
Add drying agent to the liquid, swirl gently, stopper the flask, and leave for about ten minutes.
What does it indicate if the solid drying agent sticks together in a lump?
There is still some water present.
What should you do if the drying agent clumps together?
Add more drying agent until the solid is dispersed in the solution as a fine powder.
What should be observed in the liquid after decanting from the solid if it is dry?
The liquid should be clear.
Fill in the blank: A drying agent is an _______ inorganic salt that readily takes up water to become hydrated.
anhydrous
When do you use Cacl2
you use anhydrous calcium chloride when drying hydrocarbons
When do you use CaSO4 and MgSO4?
General drying
