Iron does not rust even if zinc coating is broken in galvanized iron pipe. Explain.

Answer:

Zinc is more reactive than iron, it loses electron more readily as compared to iron. In galvanized iron object, zinc acts as anode and does not allow the iron to lose electron, i.e. makes it a cathode. So long zinc is there on surface, it reduces to Fe
2+ (if any formed) to iron back.
1001 Views

Following two reactions can occur at cathode in the electrolysis of aqueous sodium chloride:
Na+ + e → Na(s) 2H2O(l) + 2r → H2(g) + 2OH(aq)
red = – 0.83 V
Which reaction takes place preferentially and why?

Answer:

We know from electrochemical series and the standard reduction electrode potential that higher the reduction potential of a species, there is increasing tendency for its reduction to occur. Here, the standard reduction potential of water is greater than that of sodium ion, so reduction of water takes place in preference to that of sodium ion and H
2 is liberated at cathode.
134 Views

What is a primary cell? Give an example.


Answer:
A primary cell is that electrochemical cell, which cannot be recharged and the chemicals are to be replaced in it regularly. A Leclanche cell is an example of a primary cell.
148 Views

Advertisement

What is the effect of an increase in the concentration of zinc ions on the electrode potential of zinc electrode for which E° equals – 0.76 V?


Answer:

According to Nernst equation, the electrode potential of zinc electrode will increase with the increase in the concentration of zinc ions.
E = E°+2.303 RTnFlogZn2+.
137 Views

Advertisement
Express the relation between conductivity and molar conductivity of a solution. 

Answer:

Λm=1000 Km
where M is molarity of a solution.
149 Views

Advertisement