63) If n is the number of carbon atoms in the potassium salt of a carboxylic acid, then the alkane formed on electrolysis of aqueous solution of this salt would have carbon atoms equal to:

64) Ethyne can be prepared in a single step from:

65) 2,3−dibromobutane, when heated with zinc dust yields:

66) An aqueous solution of patassium salt of fumaric acid is electrolysed. The hydrocarbon produced at the anode is:

67) 2−pentyne can be converted into trans−pent−2−ene by reaction with: