In a galvanic cell, do the ions from half cell move into the salt bridge?
Answers
A salt bridge is a U- shaped tube containing concentrated solution of an inert electrolyte like KCl, KNO3, K2SO4, etc. or solidified solution of such an electrolyte in agar- agar. An inert electrolyte is one whose ions do not take part in the redox reaction and also do not react with electrolytes used. The function of the salt bridge is to allow the movement of ions from one solution to other without mixing of the two solutions.Thus,whereas electrons flow in the outer circuit in the wire, the inner circuit is completed by the flow of ions from one solution to the other through the salt bridge.Moreover,it helps to maintain the electrical neutrality of the solution in the two half cells. In salt bridge, the electrolytes like KCl, KNO3 or NH4NO3 are preferred because their ions have almost equal transport number, i.e. they move with almost same speed when an electric current flows through them.