Which of the following aqueous solutions remain alkaline after electrolysis ?

Options

A. `CH_(3)COONa`
B. `KNO_(3)`
C. `NaCl`
D. `LiF`

Answer

a,c

Explanation

`a.` Reduction potential of `H_(2)Ogt` Reduction potential of `Na^(o+)`.
Hence,
Cathode `:2H_(2)O+2e^(-) rarr 2 overset(c-)(O)H+H_(2)`
`(`Solution is basic `)`
Anode `:CH_(3)COO^(c-) overset(Kolbe's el ectrolysis)rarrC_(2)H_(6)(`Ethane`)+2CO_(2)`
`b. K^(o+)` does not undergo reductin but reduction of `H_(2)O` occurs to give `overset(c-)(O)H` ion and `H_(2)(g)`.
Similarly, `NO^(c-)._(g)`. ion does not undergo oxidation but oxidation of `H_(2)O` occurs to give `H^(o+)` ions and `O_(2)(g)`.
`H^(o+)` and `overset(c-)(O)H` ions get neutralized and `pH=7(` neutral solution `).`
`c. Na^(o+)` ions do not undergo reduction but reduction of `H_(2)O` occurs to give `overset(c-)(O)H` ions and `H_(2)(g)` . `(` Hence, solution is basic`).`
`Cl^(c-)` undergoes oxidation to give `Cl_(2)(g)`.
`d.` Same explanation as in `(b)`.