JEE Main 2019 — Chemistry Physical Chemistry

2019mcqmedium

An example of a disproportionation reaction is

Official previous-year question

Held on 12 Apr 2019 · Verified 6 Jul 2026.

Options

A
$2{\mathrm{KMnO}}_{4}\rightarrow {K}_{2}{\mathrm{MnO}}_{4}+{\mathrm{MnO}}_{2}+{O}_{2}$
B
$2{\mathrm{MnO}}_{4}^{-}+10{I}^{-}+16 {H}^{+}\rightarrow 2 {\mathrm{Mn}}^{2+}+5{I}_{2}+8{H}_{2}O$
C
$2 CuBr\rightarrow CuB{r}_{2}+Cu$
D
$2 NaBr+{Cl}_{2}\rightarrow 2NaCl+{Br}_{2}$

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Solution

Disproportionation reaction: In this type of reaction, same elemental species gets oxidised as well as reduced.

$\overset{+1}{\text{Na}}\overset{-1}{\text{Br}}+\overset{0}{{\text{Cl}}_{2}}\rightarrow 2\overset{+1}{\text{Na}}\overset{-1}{\text{Cl}}+\overset{0}{{\text{Br}}_{2}}-$ not disproportionate,

$[2K\overset{+7}{Mn}{O}_{4}\rightarrow {K}_{2}\overset{+6}{\mathrm{Mn}}{O}_{4}+\overset{+4}{Mn}{O}_{2}+{O}_{2}]-$ not disproportionate,

$2\overset{+7}{Mn}{O}_{4}^{-}+10{J}^{-}+16{H}^{+}\rightarrow 2\overset{+2}{Mn}+S{I}_{2}+8{H}_{2}O-$ not disproportionate

JEE Main 2019 Chemistry, Redox Reactions — solution figure

-It is disproportionate.

Your note

JEE Main Physical Chemistry in other years

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JEE Main 2019 — Chemistry Physical Chemistry

2019mcqmedium

An example of a disproportionation reaction is

Official previous-year question

Held on 12 Apr 2019 · Verified 6 Jul 2026.

Options

A
$2{\mathrm{KMnO}}_{4}\rightarrow {K}_{2}{\mathrm{MnO}}_{4}+{\mathrm{MnO}}_{2}+{O}_{2}$
B
$2{\mathrm{MnO}}_{4}^{-}+10{I}^{-}+16 {H}^{+}\rightarrow 2 {\mathrm{Mn}}^{2+}+5{I}_{2}+8{H}_{2}O$
C
$2 CuBr\rightarrow CuB{r}_{2}+Cu$
D
$2 NaBr+{Cl}_{2}\rightarrow 2NaCl+{Br}_{2}$

Did you get this right?

Solution

Disproportionation reaction: In this type of reaction, same elemental species gets oxidised as well as reduced.

$\overset{+1}{\text{Na}}\overset{-1}{\text{Br}}+\overset{0}{{\text{Cl}}_{2}}\rightarrow 2\overset{+1}{\text{Na}}\overset{-1}{\text{Cl}}+\overset{0}{{\text{Br}}_{2}}-$ not disproportionate,

$[2K\overset{+7}{Mn}{O}_{4}\rightarrow {K}_{2}\overset{+6}{\mathrm{Mn}}{O}_{4}+\overset{+4}{Mn}{O}_{2}+{O}_{2}]-$ not disproportionate,

$2\overset{+7}{Mn}{O}_{4}^{-}+10{J}^{-}+16{H}^{+}\rightarrow 2\overset{+2}{Mn}+S{I}_{2}+8{H}_{2}O-$ not disproportionate

JEE Main 2019 Chemistry, Redox Reactions — solution figure

-It is disproportionate.

Your note

JEE Main Physical Chemistry in other years

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JEE Main 2019 — 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

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JEE Main 2019 — 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