Which of the following statements are correct ?

Options

A. The levelling effect is not observed in nonaqueous medium
B. The strength of an acid having general formula `(HO)_(m)ZO_(n)` increases with increase in the value of n.
C. In a given reaction, the position of equilibrium favours the formation of a weak Bronsted acid and a weak Bronsted base.
D. The reaction `HCN + OH^(-) hArr CN^(-) + H_(2)O` is displaced to the right indicating that the acid strength of HCN is greater than water and the base strength `CN^(-)` is greater than that of `OH^(-)`.

Answer

B, C

Explanation

Reaction proceeds in a direction favouring weak acids and bases. So `CN^(-)` is also a weaker base then `OH^(-)`.