The value of the e.m.f of a voltaic cell, which has dilute tetraoxosulphate (VI) acid as its electrolyte and copper and zinc as its electrodes becomes less with use. Explain this observation and state how it can be corrected.
Explanation
Explanation: This is due to the accumulation of hydrogen bubbles in the positive copper plate, thereby insulating the electrodes. The hydrogen-zinc pair sets up opposing e.m.f. that reduces the e.m.f. originally established. Correction: It can be corrected by introducing a suitable depolarises.