Question

Saturated solution of $KN{O}_3$ is used to make salt bridge because:

• A. velocity of $K^{+}$ ion is greater than that of $N{O}_3^{-}$ ion
• B. velocity of $N{O}_3^{-}$ ion is greater than that of $K^{+}$ ion
• C. velocities of both $K^{+}$ and $N{O}_3^{-}$ ions are nearly the same
• D. $KN{O}_3$ is highly soluble in water

Answer 1

Answer: (C)

velocities of both $K^{+}$ and $N{O}_3^{-}$ ions are nearly the same

For a good salt bridge, the velocities of ions should be same. If the velocities are not same, then the ions would not be able to neutralize the charge equally in both half cells. Consequently, an opposite force would be developed that restricts the flow of current. For $KN{O}_3$, the velocities of $K^{+}$ and $N{O}_3^{-}$ are nearly same. Therefore, it is used to make salt bridges.

Hence, option c is correct.