Question

a) If diethyl ether (10 mL) and water (10 mL) is mixed, which compound will be in the top layer? If dichloromethane and sodium hydroxide (10 mL, 1M) solution is mixed, what is in top layer?

b) If methanol (10 mL) and water (10 mL) is mixed, will you see two layers? Why?

Answer 1

(a).The density of diethyl ether is 0.713 g /ml while that of water is 1.00 g/ml .They form immiscible solutions where each of them do not mix thus stand as two separate layers. Obviously, diethyl ether will form the top layer while water remains at bottom being more dense.

Usually chlorinated organic solvents are more dense than water. dichloromethane has density of 1.33 g/ml while 1 M NaOH solution has a density of 1.04 g/ml. They again form  immiscible solution with NaOH solution at the top layer.

(b). Alcohols though being organic compounds show exceptional solubility in water when their hydrocarbon chain is short. Ex: methanol, ethanol. These alcohols mix with water in all proportions due to extensive intermolecular hydrogen bonding formation. We observe a single homogeneous layer upon mixing them.