Match List-I with List-II.
| List-I | List-II |
| (i) \(\Lambda_{m}\) | (a) S cm−1 |
| (ii) Ecell | (b) m−1 |
| (iii) \(\kappa\) | (c) S cm2 mol−1 |
| (iv) G* | (d) V |
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → i-c, ii-d, iii-a, iv-b
The unit of each quantity follows from the way it is defined.
(i) \( \Lambda_m \) — This matches (c) S cm2 mol−1. Molar conductivity is conductivity divided by concentration:
\( \displaystyle \Lambda_m=\frac{\kappa}{c}=\frac{\mathrm{S\,cm^{-1}}}{\mathrm{mol\,cm^{-3}}}=\mathrm{S\,cm^{2}\,mol^{-1}} \)
(ii) Ecell — This matches (d) V. The cell potential is a potential difference between the two electrodes, measured in volts.
(iii) \( \kappa \) — This matches (a) S cm−1. Conductivity is the inverse of resistivity; its SI unit is S m−1, and it is often expressed in S cm−1.
(iv) G* — This matches (b) m−1. The cell constant is l/A, a length divided by an area, so its dimension is length−1.
NCERT (2026-27 edition):
2.4.1 Measurement of the Conductivity of Ionic Solutions – “… If we use S cm–1 as the units for κ and mol cm–3, the units of concentration, then the units for Λm are S cm2 mol–1.”
2.2 Galvanic Cells – “The potential difference between the two electrodes of a galvanic cell is called the cell potential and is measured in volts.”
2.4 Conductance of Electrolytic Solutions – “… The inverse of resistivity, called conductivity (specific conductance) is represented by the symbol, κ (Greek, kappa). … The SI units of conductivity are S m–1 but quite often, κ is expressed in S cm–1.”
2.4.1 Measurement of the Conductivity of Ionic Solutions – “The quantity l/A is called cell constant denoted by the symbol, G*. It depends on the distance between the electrodes and their area of cross-section and has the dimension of length–1 and can be calculated if we know l and A.”