Question

Saturated solution of $KN{O}_3$ with agar-agar is used to make "salt bridge" because

• A. Size of $K^{+}$ is greater than that of $N{O}_3^{-}$
• B. Velocity of $K^{+}$ is greater than that of $N{O}_3^{-}$
• C. Velocities of $K^{+}$ and $N{O}_3^{-}$ are nearly same
• D. Both the velocities and sizes of $K^{+}$ and $N{O}_3^{-}$ are nearly same

Answer 1

The correct option is C Velocities of $K^{+}$ and $N{O}_3^{-}$ are nearly same

The main function of salt bridge is to maintain neutrality of the system . So, it provides negative ions to excess positive charge and positive ions to excess negative charge, hence, keeping the system neutralised. The system gets neutralised only only when the velocities of $K^{+}$ and $N{O}_3^{-}$ are same.