Assertion `(A):` When an aqueous solution of `KNO_(3)` is electrolyzed, potassium is liberated at the cathode.
Reason `(R): K^(+)` ions are discharged at cathode and `NO_(3)^(-)` at anode.

Options

A. If both `(A)` and `(R)` are correct, and `(R)` is the correct explanation of `(A)`.
B. If both `(A)` and `(R)` are correct, but `(R)` is not the correct explanation of `(A)`.
C. If `(A)` is correct, but `(R)` is incorrect.
D. If `(A)` is incorrect, `(R)` is correct.

Answer

D

Explanation

`(A)` is incorrect, since in aqueous solution reduction of `H_(2)O` occurs as
`H_(2)O +e^(-) rarr overset(c-)(O)H+(1)/(2)H_(2)(g)`
`(R)` is correct but not the explanation of `(A)` since it is independent statement not related to `(A)`. `+ve` ions undergo reductino at cathode and `-ve` ions undergo oxidation at anode.