NEET UG 2019 — Chemistry Physical Chemistry

2019mcqhard

The standard electrode potential $\left(\mathrm{E}^{-}\right)$ values of $\left(\mathrm{Al}^{3+} / \mathrm{Al}, \mathrm{Ag}^{+} / \mathrm{Ag}, \mathrm{K}^{+} / \mathrm{K}\right.$ and $\mathrm{Cr}^{3+} / \mathrm{Cr}$ are $-1.66 \mathrm{~V}, 0.80 \mathrm{~V}, 2.93 \mathrm{~V}$ and $-0.74 \mathrm{~V}$ , respectively. The correct decreasing order of reducing power of the metal is

Official previous-year question

Held on 30 Apr 2019 · Verified 9 Jul 2026.

Options

A
$\mathrm{Ag}>\mathrm{Cr}>\mathrm{Al}>\mathrm{K}$
B
$\mathrm{K}>\mathrm{Al}>\mathrm{Cr}>\mathrm{Ag}$
C
$\mathrm{K}>\mathrm{Al}>\mathrm{Ag}>\mathrm{Cr}$
D
$\mathrm{Al}>\mathrm{K}>\mathrm{Ag}>\mathrm{Cr}$

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Solution

More negative the value of standard reduction potential, higher is the reduction power. i.e. Reducing power $\propto \frac{1}{\text { standard reduction potential }}$ Thus, the correct decreasing order of reducing power of the metal is $\begin{aligned} & \begin{array}{llll} \mathrm{K} & > & \mathrm{Al} & > \end{array} \\ & \left(\mathrm{E}_{\mathrm{K}^{+} / \mathrm{K}}^0=-2.93 \mathrm{~V}\right) \quad\left(\mathrm{E}_{\mathrm{Al}^{3+} / \mathrm{Al}}^0=-1.66 \mathrm{~V}\right) \\ & \mathrm{Cr}>\mathrm{Ag} \\ & \left(\mathrm{E}_{\mathrm{Cr}^{3+} / \mathrm{Cr}}^0=-0.74 \mathrm{~V}\right) \quad\left(\mathrm{E}_{\mathrm{Ag}^{+}}^0 / \mathrm{Ag}=0.80 \mathrm{~V}\right) \\ & \end{aligned}$

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NEET UG 2019 — Chemistry Physical Chemistry

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NEET UG 2019 — Chemistry Physical Chemistry

Options

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Solution

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More NEET UG Physical Chemistry questions

Other Chemistry topics for NEET UG

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