What is Galvanic cell? Give an example.
The Galvanic cell is a device by this device the redox reactions take place indirectly and so the decrease of free energy appears in the form of electrical energy
Ex: -       In Zn –Cl electro chemical cell; Zn plate immersed in 1 MZnSO4 acts as anode whereas Cu plate immersed in 1 MZnSO4 acts as cathode in separate containers these are connected through a galvanometer. A salt bridge is also placed with its ends immersed in the two electrode solutions.
Why an electrochemical cell becomes dead after sometimes?
As the cell works, the concentration of ions in one half cells goes on increasing and that in the other goes on decreasing. Thus, the electrode potentials go on changing till they becomes equal and thus, the net cell potential becomes zero.
Can we store copper sulphate solution in zinc vessel?
Zinc is more electro positive than copper and thus Zn will dissolve in it to form ZnSO4
Thus      CuSO4 (aq)  + Zn (s)    ž   ZnSO4 (aq) + Cu (s)
Thus, CuSO4 solution cannot be stored in zinc vessel.
Why iron reacts with dilute HCl to gives H2 gas while Cu does not?
Iron lies above hydrogen in the emf series. Being more electro positive than hydrogen it displaces hydrogen from HCl. Copper which lies below cannot displace hydrogen from HCl.
The electrical conductivity of a metal is greater than that of its solution. Explains.
The conductance of a metal of a metal is due to the movement of electrons while the conductance of a solution is due to the movement of ions. Since electrons are lighter than ions, they move faster and conduct more electricity.
Which solution has more electrical conductivity 0.01 M KCl or 0.02 M KCl at the same temperature?
The electrical conductivity depends upon the number of ions per unit volume of the solutions. Since 0.02 M solution has more ions per unit volume, its electrical conductivity is more.
Explain with a suitable example, the term cathodic reductions
When electric current is passed through the electrolyte, the cations move towards cathode. Here, they gain electrons and get reduced. The term is called cathodic reductions
Ex:- In Zn –Cu cell, Cu2+ ions are produced at cathode. Cu2+ (aq)  + 2e   ž  Cu (s)
What is kohlrausch’s law?
At an infinite dilution, when the dissociation is complete, each ion makes a definite contribution towards molar conductance of the electrolyte irrespectively of the nature of the other ion with which it is associated.
Define molar conductance.
It is defined as the conductance due to all the ions in solution which contains one gm molecules of the electrolyte at a particular temperature.
Define Equivalent conductance.
It is the conductance due to all the ions in which contains one gm equivalent of the electrolyte at a particular temperature.





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