NEET Chemistry - New - Redox Reactions

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Question - 1

For the redox reaction MnO4- + C2O42- + H+ ⟶ Mn2+ + CO2 + H2O. The correct coefficients of the reactants for the balanced equation are:

  • A MnO4- C2O42-  H+ 2 5 16
  • B MnO4- C2O42- H+ 16 5 2
  • C MnO4- C2O42- H+ 5 16 5
  • D MnO4-  C2O42- H+ 2 15 5

Question - 2

Consider the change in oxidation state of Bromine corresponding to different emf values as shown in the diagram below: 
\({ BrO }_{ 4 }^{ - }\underrightarrow { 1.82\quad V } { BrO }_{ 3 }^{ - }\underrightarrow { 1.5\quad V } { HBrO }\underrightarrow { 1.595\quad V } { Br }_{ 2 }\underrightarrow { 1.0652\quad V } { Br }^{ - }\) Then the species undergoing disproportionation is:

  • A BrO3-
  • B BrO4-
  • C Br2
  • D HBrO

Question - 3

Hot concentrated, sulphuric acid is a moderately strong oxidizing agent. Which of the following reactions do not show oxidizing behaviour?

  • A Cu + 2H2SO4 ⟶ CuSO4 + SO2 + 2H2O
  • B S + 2H2SO4 ⟶ 3SO2 + 2H2O
  • C C + 2H2SO4 ⟶ CO2 + 2SO2 + 2H2O
  • D CaF2+ H2SO4 ⟶CaSO4 + 2HF

Question - 4

The pair of compounds that can exist together is :

  • A FeCl3, SnCl2
  • B HgCl2, SnCl2
  • C FeCl2, SnCl2
  • D FeCl3, KI

Question - 5

In acidic medium, H2O2 changes Cr2O72- to CrO5, which has two ( __O__O__) bonds. The oxidation state of Cr in CrO5 is:

  • A +5
  • B +3
  • C +6
  • D -10

Question - 6

(I) H2O2 + O3 ⟶ H2O + 2O2
(II) H2O2 + Ag2O ⟶ 2Ag + H2O + O2 
Role of hydrogen peroxide in the above reaction is respectively:

  • A Oxidising in (I) and reducing in (II)
  • B Reducing in (I) and oxidizing in (II)
  • C Reducing in (I)and (II)
  • D Oxidising in (I) and (II)

Question - 7

When Cl2 reacts with hot and concentrated sodium hydroxide solution, the oxidation number of chlorine changes from:

  • A Zero to + 1 and Zero to - 5
  • B Zero to -1 and Zero to +5
  • C Zero to -1 and Zero to +3
  • D Zero to + 1 and Zero to -3

Question - 8

Oxidation number of P in PO43-, of 5 in SO42- and that of Cr in Cr2O72- are respectively:

  • A +3, +6 and +5
  • B +5, +3 and +6
  • C -3, +6 and +6
  • D +5, +6 and +6

Question - 9

Number of moles of MnO4- required to oxidize one mole of ferrous oxalate completely in acidic medium will be:

  • A 7.5 moles
  • B 0.2 moles
  • C 0.6 moles
  • D 0.4 moles

Question - 10

Which of the following is the best description of the behaviour of bromine in the reaction given below?
H2O + Br2 ⟶ HOBr + HBr

  • A Proton accepter only
  • B Both oxidized and reduced
  • C Oxidised only
  • D Reduces only
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