Dehydration comes under elimination reaction and hence it does not come under addition reaction.

Classes of organic compounds are those which involves organic compounds such as carbon, hydrogen and oxygen. Hence, electro compounds is not a class of organic compounds.

Isocyanide is a compound and it is not a functional group.

Because like dissolve like, Diethyl ether is very non-polar compared to water so it will dissolve the non-polar substances and precipitate the ionic compounds. Since like dissolves like, your barely-polar organic ether is often happy to dissolve your non-polar organic molecules.

Acute chloroform intoxication can cause depression of the central nervous system and may lead to death from lethal arrhythmias or respiratory arrest. Thus, the organic solvent is no longer in clinical use as an anesthetic, but still plays a role in cases of suicide, homicide, or inhalation for psychotropic effects.