1
COMEDK 2025 Evening Shift
MCQ (Single Correct Answer)
+1
-0

Identify the correct coefficients (a), (b), (c) and (d) in the following equations

i) $\quad \mathrm{xMnO}_4^{--}+$(a) $\mathrm{SO}_3{ }^{2-}+$ (b) $\mathrm{H}^{+} \cdots \longrightarrow \mathrm{xMn}^{2+}+$ (a) $\mathrm{SO}_4{ }^{2-}+$ (c) $\mathrm{H}_2 \mathrm{O}$

ii) (c) $\mathrm{S}_2 \mathrm{O}_3{ }^{2-}+$ (d) $\mathrm{MnO}_4^{-}+\mathrm{H}_2 \mathrm{O} \cdots \rightarrow$ (d) $\mathrm{MnO}_2+$ (b) $\mathrm{SO}_4{ }^{2-}+\mathrm{xOH}^{-}$

A
$(a)=3$ (b) $=8$ $(c)=6$ $(d)=6$
B
$(a)=5$ (b) $=6$ $(c)=3$ $(\mathrm{d})=8$
C
(a) $=2$ (b) $=8$ $(c)=4$ $(\mathrm{d})=4$
D
$(a)=2$ (b) $=6$ $(c)=6$ $(d)=5$
2
COMEDK 2025 Evening Shift
MCQ (Single Correct Answer)
+1
-0
An example of disproportionation reaction is :
A
$2 \mathrm{H}_2 \mathrm{O}_2 \rightarrow 2 \mathrm{H}_2 \mathrm{O}+\mathrm{O}_2$
B
$2 \mathrm{KMnO}_4 \rightarrow \mathrm{~K}_2 \mathrm{MnO}_4+\mathrm{MnO}_2+\mathrm{O}_2$
C
$2 \mathrm{MnO}_4^{-}+10 \mathrm{I}^{-}+16 \mathrm{H}^{+} \rightarrow 2 \mathrm{Mn}^{2+}+5 \mathrm{I}_2+8 \mathrm{H}_2 \mathrm{O}$
D
$2 \mathrm{NaI}+\mathrm{Cl}_2 \rightarrow 2 \mathrm{NaCl}+\mathrm{I}_2$
3
COMEDK 2025 Evening Shift
MCQ (Single Correct Answer)
+1
-0
The oxidation number of potassium in $\mathrm{K}_2 \mathrm{O}, \mathrm{K}_2 \mathrm{O}_2$ and $\mathrm{KO}_2$ respectively are:
A
$+1,+2,+4$
B
$+1,+2,+1$
C
$+1,+1,+1$
D
$+2,+1,+1$
4
COMEDK 2025 Afternoon Shift
MCQ (Single Correct Answer)
+1
-0

Given below are 2 statements: one Assertion and the other Reason. Which one of the following options is correct?

Assertion : Sulphur dioxide and Hydrogen peroxide can act as both oxidising and reducing agents but Nitric acid can act as only oxidising agent.

Reason : Sulphur and Oxygen can exhibit more than one stable oxidation states while Nitrogen does not.

A
Assertion is correct but Reason is wrong.
B
Both Assertion and Reason are wrong.
C
Both Assertion and Reason are correct.
D
Assertion is wrong but Reason is correct.
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