Question 1

What is the difference between conductance and molar conductivity?

Accepted Answer

Conductance, G, is the ability of the complete cell to carry current and depends on electrode area and separation. Molar conductivity normalises the solution property to molar concentration using Lambda m = 1000 kappa / C.

Question 2

How is specific conductivity related to conductance?

Accepted Answer

The relation is G = kappa A/l. Therefore kappa = G l/A, and l/A is called the cell constant.

Question 3

Why does molar conductivity of NaCl increase on dilution?

Accepted Answer

Upon dilution, ions become less crowded and their interactions decrease, allowing them to migrate more independently. As a result, the molar conductivity of NaCl rises toward its limiting value.

Question 4

How is limiting molar conductivity obtained for a strong electrolyte?

Accepted Answer

For a strong electrolyte, molar conductivity is plotted against the square root of concentration. The approximately straight line is extrapolated to zero concentration, where its y-intercept gives the limiting molar conductivity.

Question 5

What is Kohlrausch's independent migration law?

Accepted Answer

At infinite dilution, ions migrate independently. The limiting molar conductivity is the sum of limiting ionic conductivities weighted by the stoichiometric coefficients: Lambda m degree = nu+ lambda+ degree + nu- lambda- degree.

Conductance & Kohlrausch's Law in 3D — Ions, Bulbs, Limiting Conductivity

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