Redox Reactions · JEE Main previous year questions

2020 5 questions

1. Q592020 · 6 Sept 2020 · Shift 1

   The lanthanoid that does NOT show +4 oxidation state is :

   1. A.Tb
   2. B.Dy
   3. C.Ce
   4. D.Eu
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   Answer: D

2. Q732020 · 2 Sept 2020 · Shift 1· Numerical answer

   The oxidation states of iron atoms in compounds (A), (B) and (C), respectively, are x, y and z. The sum of x, y and z is ____. $\mathrm{N}{\mathrm{a}}_4[\mathrm{Fe}(\mathrm{CN}{)}_5(\mathrm{NOS})]$ (A) $\mathrm{N}{\mathrm{a}}_4[\mathrm{Fe}{\mathrm{O}}_4]$ (B) $[\mathrm{F}{\mathrm{e}}_2(\mathrm{CO}{)}_9]$ (C)

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   Answer: 6

3. Q652020 · 9 Jan 2020 · Shift 1

   The compound that cannot act both as oxidising and reducing agent is :

   1. A.${\mathrm{H}}_3\mathrm{P}{\mathrm{O}}_4$
   2. B.${\mathrm{H}}_2\mathrm{S}{\mathrm{O}}_3$
   3. C.${\mathrm{H}}_2{\mathrm{O}}_2$
   4. D.$\mathrm{HN}{\mathrm{O}}_2$
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   Answer: A

4. Q532020 · 7 Jan 2020 · Shift 1

   Oxidation number of potassium in ${\mathrm{K}}_2\mathrm{O}$, ${\mathrm{K}}_2{\mathrm{O}}_2$ and $\mathrm{K}{\mathrm{O}}_2$ respectively is :

   1. A.+1, +2 and + 4
   2. B.+1, +1 and + 1
   3. C.+2, +1 and $+\frac{1}{2}$
   4. D.+1, +4, and +2
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   Answer: B

5. Q592020 · 7 Jan 2020 · Shift 2

   The redox reaction among the following is :

   1. A.reaction of ${\mathrm{H}}_2\mathrm{S}{\mathrm{O}}_4$ with $\mathrm{NaOH}$.
   2. B.formation of ozone from atmospheric oxygen in the presence of sunlight.
   3. C.combination of dinitrogen with dioxygen at 2000 K
   4. D.reaction of $[\mathrm{Co}({\mathrm{H}}_2\mathrm{O}{)}_6]\mathrm{C}{\mathrm{l}}_3$ With $\mathrm{AgN}{\mathrm{O}}_3$
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   Answer: C