Salt Bridge
o These electrodes behave as terminal to hold the electrons . o The two electrodes are connected via wire . o
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A salt bridge is placed between the two beakers . This provides a path for the movement of ions from one beaker to the other in order to maintain electrical neutrality .
Zinc electrode gets oxidized and hence releases electrons that flow through the wire towards the copper electrode .
The copper ( II ) sulphate solution releases copper ions Cu 2 + .
o At the anode :
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Oxidation ---------------- loss of electrons . Zn -- > Zn 2 + + 2e -
At cathode ,
Reduction -------------gain of electrons .
Cu 2 + + 2e - -- > Cu
Zinc atoms being more reactive have a greater tendency to lose electrons than that of copper . The electrons in this cell moves from zinc anode to copper cathode through the wire connecting the two electrodes in the external circuit
A bulb placed within this circuit will glow and a voltmeter connected within this circuit will show deflection .
o The net reaction of this cell is the sum of two half-cell reactions . Zn ( s ) + Cu 2 + ( aq ) -- > Zn 2 + ( aq ) + Cu ( s )
In a Daniel cell a salt bridge is placed between the two beakers containing a solution of zinc sulphate ( ZnSO4 ) and a solution of copper ( II ) sulphate respectively . This provides a path for the movement of ions from one beaker to the other in order to maintain electrical neutrality .
Salt Bridge