Which one of the following statements given below regarding properties of solutions, describes a

colligative effect?

(1) Boiling point of pure water decreases by the ~9dition of ethanol.

(2) Vapour pressure of pure water decreases by the addition of nitric acid.

(3) Vapour pressure of pure benzene decreases by the addition of naphthalene.

(4) Boiling point of pure benzene increases by the addition of toluene.