JEE Main 2006 — Chemistry Physical Chemistry

2006mcqhard

Resistance of a conductivity cell filled with a solution of an electrolyte of concentration $0.1 \mathrm{M}$ is $100 \Omega$ . The conductivity of this solution is $1.29 \mathrm{~S} \mathrm{~m}^{-1}$ . Resistance of the same cell when filled with $0.2 \mathrm{M}$ of the same solution is $520 \Omega$ . The molar conductivity of $0.02 \mathrm{M}$ solution of the electrolyte will be

Official previous-year question

Held on 30 Apr 2006 · Verified 6 Jul 2026.

Options

A
$124 \times 10^{-4} \mathrm{~S} \mathrm{~m}^2 \mathrm{~mol}^{-1}$
B
$1240 \times 10^{-4} \mathrm{~S} \mathrm{~m}^2 \mathrm{~mol}^{-1}$
C
$1.24 \times 10^{-4} \mathrm{~S} \mathrm{~m}^2 \mathrm{~mol}^{-1}$
D
$12.4 \times 10^{-4} \mathrm{~S} \mathrm{~m}^2 \mathrm{~mol}^{-1}$

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Solution

There is one mistake in Question paper. Assuming concentration of solution is $0.2 \mathrm{M}$ instead of $0.02 \mathrm{M}$ . Since resistance of $0.2 \mathrm{M}$ is $520 \Omega$ . $\begin{aligned} \mathrm{R} & =100 \Omega \\ \mathrm{K} & =\frac{1}{\mathrm{R}}\left(\frac{\ell}{\mathrm{a}}\right) \\ 1.29 & =\frac{1}{100}\left(\frac{\ell}{\mathrm{a}}\right) \\ \left(\frac{\ell}{\mathrm{a}}\right) & =129 \mathrm{~m}^{-1} \\ \mathrm{R} & =520 \Omega, \mathrm{C}=0.2 \mathrm{M} \\ \mathrm{K} & =\frac{1}{\mathrm{R}}\left(\frac{\ell}{\mathrm{a}}\right)=\frac{1}{520}(129) \Omega^{-1} \mathrm{~m}^{-1} \\ \mu & =\mathrm{K} \times \mathrm{V}_{\text {in } \mathrm{cm}} \\ & =\frac{1}{520} \times 129 \times \frac{1000}{0.2} \times 10^{-6} \mathrm{~m}^3 \\ & =\frac{129}{520} \times \frac{1000}{0.2} \times 10^{-6} \\ & =1.24 \times 10^{-3} \\ & =12.4 \times 10^{-4} \end{aligned}$

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Options

$124 \times 10^{-4} \mathrm{~S} \mathrm{~m}^2 \mathrm{~mol}^{-1}$

$1240 \times 10^{-4} \mathrm{~S} \mathrm{~m}^2 \mathrm{~mol}^{-1}$

$1.24 \times 10^{-4} \mathrm{~S} \mathrm{~m}^2 \mathrm{~mol}^{-1}$

$12.4 \times 10^{-4} \mathrm{~S} \mathrm{~m}^2 \mathrm{~mol}^{-1}$

Solution

JEE Main 2006 — Chemistry Physical Chemistry

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Solution

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JEE Main 2006 — Chemistry Physical Chemistry

Options

Did you get this right?

Solution

Your note

JEE Main Physical Chemistry in other years

More JEE Main Physical Chemistry questions

Other Chemistry topics for JEE Main

Organic Chemistry

Inorganic Chemistry

Keep practicing Physical Chemistry