Assertion (A) `:` pH of aqueous solutin decreases when NaCN is added to it .
Reason (R ) `:` NaCN provides a common ion to HCN.

Assertion (A): pH value of HCN solution decreases when NaCN is added to it. Reason (R) : NaCN provides a common ion CN^(Theta) .

Assertion (A): pH value of HCN solution decreases when NaCN is added to it. Reason (R) : NaCN provides a common ion CN^(Theta) to HCN .

Assertion (A) : P^(H) of an aqueous solution of acetic acid remians unchanged on the addition of sodium acetate. Reason ( R ) : Dissociation of acetic acid is supressed by the addition of soidum acetate due to common ion effect.

Assertion (A) The aqueous solution of CH_(3)COONa is alkaline in nature. Reason (R) Acetate ion undergoes atomic hydrolysis.