Answers are given in the end
1.What is NFE/SHE ?
2.Explain the variation of conductivity with dilution. or How does conductivity varies with dilution ? Explain the reason for the variation ?
3.Explain the variation of molar conductivity of weak electrolyte with dilution. or How does conductivity of weak electrolyte varies with dilution ? Explain the reason for the variation ?
4.Explain the variation of molar conductivity of strong electrolyte with dilution. or How does conductivity of strong electrolyte varies with dilution ? Explain the reason for the variation ?
5.Explain Kohlrausch law
6.Calculate the Vont hoff’s factor for K4[Fe{CN)6] .
7.What is cell constant ?
8.Why can’t molar conductivity at infinite dilution of weak electrolyte be measured using graphical method ?
9.What are the secondary cells?
10. What are the fuel cells?
11.State advantages and disadvantages of fuel cells.
Answers- 1.The hydrogen electrode at 298 K with pressure of hydrogen is 1 bar and concentration of hydrogen is 1 M is called Standard Hydrogen Electrode / Normal Hydrogen Electrode. 2.Conductivity decrease with dilution because number of ions decreases per unit volume with dilution. ( Conductivity is the conductance of solution of unit volume/ one litre. 3. Molar conductivity of weak electrolyte increases with dilution due to increase in degree of dissociation. 4.Molar conductivity of strong electrolyte increases with dilution due to decrease in interionic attraction as interionic distance increase with dilution. 5.At infinite dilution molar conductivity of weak electrolyte is sum of contribution of molar conductivities of cations and anions which are independent of each other. 6. Von,t Hoff factor = 5/1 =5. 7. Cell constant is the ratio of length between vs area of electrode = L / A 8.Because line of graph never touch molar conductivity axes. 9.The cell which can be reuse again and again by charging. 10. The cell which generate energy from fuel without burning it , is called fuel cell. 11. Advantage of fuel cell-(1) It is pollution free (2) Continuous source of electricity (3) byproduct is water. Disadvantages of fuel cell- It is costly as catalysts is costly.
CHEMIGOD 