Short Answer Type(a) Define molar conductivity of a solution and explain how molar conductivity changes with a change in concentration of solution for a weak and a strong electrolyte.
(b) The resistance of a conductivity cell containing 0.001 M KCl solution at 298 K is Ω 1500 . What is the cell constant if the conductivity of 0.001 M KCl solution at 298 K is 0.146x10-3 S cm-1?
The chemistry of corrosion of iron is essentially an electrochemical phenomenon. Explain the reactions occurring during the corrosion of iron in the atmosphere.
The process of corrosion is a redox reaction and involves simultaneous oxidation and reduction reactions. It can, therefore, be referred to as an electrochemical reaction.
In the process of corrosion, due to the presence of air and moisture, oxidation takes place at a particular spot of an object made of iron. That spot behaves as the anode. The reaction at the anode is can be written as follows.
Anode reaction:
Electrons released at the anodic spot move through the metallic object and go to another spot of the object. There, in the presence of H+ ions, the electrons reduce molecular oxygen. This spot behaves as the cathode. These H+ ions come either from H2CO3, which are formed due to the dissolution of carbon dioxide from the air into water or from the dissolution of other acidic oxides from the atmosphere in water.
The reaction corresponding at the cathode is written as follows.
Cathode reaction:
Also, ferrous ions are further oxidised by atmospheric oxygen to ferric ions.
These ferric ions combine with moisture, present in the surroundings, to form a hydrated ferric oxide (Fe2O3, x H2O) i.e., rust.
Determine the values of equilibrium constant (KC) and 
G° for the following reaction: 
The conductivity of 0.20 mol L-1 solution of KCl is 2.48 x 10-2 S cm-1. Calculate its molar conductivity and degree of dissociation (K+) = 73.56 S cm2 mol-1 and (Cl-)= 76.5 S
(b) What type of battery is mercury cell? Why is it more advantageous than dry cell?
The standard electrode potential (E°) for Daniell cell is +1·1 V. Calculate the G° for the reaction
Zn(s) + Cu2+ (aq) ----> Zn+ (aq) + Cu (s)
(1 F = 96500 C mol-1).
Calculate the emf of the following cell at 25°C:
Given E°cell = + 0.46 V and log 10n = n
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