Please explain this er, viz., 05, i.e., they move with almost

Priyanshu kumar Best Answer

First, it is important to put ionic species into the salt bridge that will not be reduced or oxidized in either of the half cells. Alkali cations and halide anions would be ideal for this purpose. It is also important that the charge balance in each of the half cells facilitated by the ions in the salt bridge occurs at the same rates. That means that the halide anions moving from the salt bridge into the anode to balance out the excess Zn2+ ions do so at the same rate as the alkali cations moving from the salt bridge into the cathode to balance out the depletion of Cu2+ ions. Ions have a property known as mobility and the mobility of an ion depends on its size. Smaller ions have a higher mobility than larger ions. That means that the ideal species for a salt bridge should have a cation and anion of the same size and charge. Potassium chloride is the ideal species for incorporation into a salt bridge, as K+ and Cl– have the same number of electrons and are approximately the same size. Potassium nitrate (K+NO3–) can also be used in a salt bridge. Amazingly, the nitrate ion, which has atoms with second shell electrons, has approximately the same size as a chloride ion, which has atoms with third shell electrons. Hence, the electrolytes which are choosen in which both cation and anion have similar size and charge and contain similar transport number so that they can move with same speed and perform the work i.e maintaining the electrical neutrality.