Although caffeine is soluble in water 2 g100 g of cold water

Although caffeine is soluble in water (2 g/100 g of cold water), it is more soluble in the organic solvent dichloromethane (14 g/100 g). Thus caffeine can be extracted from the basic tea solution with dichloromethane, but the sodium salts of the tannins remain behind in the aqueous solution. Evaporation of the dichloromethane yields crude caffeine; the crude material can be purified by sublimation (see Experiment 13). student used 8.23 g of tea leaves in the experiment. How much caffeine is expected, assuming all the caffeine is extracted? (Hint: See the Background section.) 5. A

Solution

Given that, 14gm of caffeine is soluble in 100gm of dichloromethane.

If the tea sample used by student weighs 8.23gm then,

In 1gm of dichloromethane, 0.14gm of caffeine is soluble ...

With the help of tea solution with dichloromethane, caffeine can be extracted such that...

When 8.23gm of tea leaves are taken the ratio will be the same.....

Such that ....amount of caffeine extracted = 8.23*0.14= 1.1522 gm [Ans]