22. The pinacol rearrangement proceeds via ________ route. (A) an electrophilic substitution (B) a free radical (C) a cycloaddition (D) a carbocation (E) a carbanion

19. Pentane can be distinguished from ethyl ether by the following test: (A) Only ether liberates hydrogen when sodium is added. (B) Only ether dissolves in concentrated sulfuric acid. (C) Only ether gives a positive iodoform test. (D) Only ether is reduced by sodium borohydride. (E) Only ether is oxidized by aqueous dichromate.