Chemistry · Ch 5 — Electrochemistry
Salt bridge
Salt bridge
In a galvanic cell the two solutions are connected by a salt bridge. It is a U tube containing a saturated solution of an inert electrolyte, such as KCl or , and 5 % agar solution. The ions of the inert electrolyte do not react with the ions of the electrode solutions or with the electrodes.
The salt bridge is prepared by filling the U tube with a hot saturated solution of the salt and agar-agar, and allowing it to cool. The cooled solution sets into a gel which does not come out on inverting the tube. The salt bridge is kept dipped in distilled water when not in use, as shown in Fig. 5.5.
Drawn by us to help you understand the concept clearly, and verified to make sure it's accurate. For exams, practice from your textbook's own diagram.
What this figure shows. The U tube filled with saturated KCl solution + agar gel (the gelled inert electrolyte), its two open ends closed with glass wool plugs, kept dipped in distilled water in a beaker when the bridge is not in use — exactly as describ …
Functions of salt bridge
The salt bridge serves the following functions : …