Match List-I with List-II
|
List-I Material |
List-II Conductivity/\( Sm^{-1} \) at 298K |
|
(A) Gold |
(I) \( 4.5 × 10^3 \) |
|
(B) Glass |
(II) \( 3.5 × 10^{-5} \) |
|
(C) Silicon |
(III) \( 1.0 × 10^{-16} \) |
|
(D) Pure water |
(IV) \( 1.5 × 10^{-2} \) |
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → (A)-(I), (B)-(III), (C)-(IV), (D)-(II)
Materials are classified by the size of their conductivity. Metals are conductors with very large conductivity; glass and ceramics are insulators with very low conductivity; silicon is a semiconductor, in between. Pure water conducts only through the few \( \ce{H3O+} \) and \( \ce{OH-} \) ions from its self-ionisation, so its conductivity is low.
(A) Gold — This matches (I) \(4.5 \times 10^3\). A metal, with the largest value in the list.
(B) Glass — This matches (III) \(1.0 \times 10^{-16}\). An insulator, with the smallest value.
(C) Silicon — This matches (IV) \(1.5 \times 10^{-2}\). A semiconductor, between metals and insulators.
(D) Pure water — This matches (II) \(3.5 \times 10^{-5}\). It has very few ions, so it conducts far less than silicon but far more than glass.
Shortcut: Gold has the largest value, (A)-(I): Options (1) and (3). Glass has the smallest, (B)-(III), which leaves Option (3).
NCERT (2026-27 edition):
Conductance of Electrolytic Solutions – …
