Q88 (2024)
The values of conductivity of some materials at $298.15\text{ K}$ in $\text{S m}^{-1}$ are $2.1 \times 10^3, 1.0 \times 10^{-16}, 1.2 \times 10, 3.91, 1.5 \times 10^{-2}, 1 \times 10^{-7}, 1.0 \times 10^3$. The number of conductors among the materials is ________
### Core Logic
Materials are classified based on their electrical conductivity at room temperature:
- Conductors: Conductivity range is generally between $10^4$ to $10^7\text{ S m}^{-1}$ for metals, but aqueous electrolytes and certain semi-metals fall in the intermediate $1$ to $10^3\text{ S m}^{-1}$ range broadly qualifying as conductors in the context of typical chemical classifications.
- Semiconductors: $10^{-6}$ to $10^4\text{ S m}^{-1}$
- Insulators: $10^{-20}$ to $10^{-10}\text{ S m}^{-1}$
Wait, typical values for metallic conductors are high, but comparing them strictly against the NCERT table:
$2.1 \times 10^3$ (Conductor)
$1.2 \times 10$ (Conductor)
$3.91$ (Conductor)
$1.0 \times 10^3$ (Conductor)
$1.0 \times 10^{-16}$ (Insulator)
$1.5 \times 10^{-2}$ (Semiconductor)
$1.0 \times 10^{-7}$ (Semiconductor / Insulator)
### Step 1: Final Counting
The materials with conductivities $2.1 \times 10^3$, $1.2 \times 10$, $3.91$, and $1.0 \times 10^3$ fall into the category of conductors.
Therefore, the number of conductors is $4$.
### Evaluation Rubric / Model Answer
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### Chapter Mix
Class 12 Chemistry: Solid State
Class 12 Chemistry: Electrochemistry
