Redox Reactions

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

• oxidising in (I) and reducing (II)

• reducing (I) and oxidizing in (II)

• reducing in (I) and (II)

• reducing in (I) and (II)

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

• zero to +1 and zero to -5

• zero to -1 and zero to +5

• zero to -1 and zero to +5

• zero to -1 and zero to +5

In which of the following compounds, nitrogen exhibits highest oxidation state?

• N₂H₄

• NH₃

• N₃H

• N₃H

A mixture of potassium chlorate, oxalic acid and sulphuric acid is heated. During the reaction which element undergoes a maximum change in the oxidation number?

• S

• H

• Cl

• Cl

For the redox reaction

$Mn{O}_4^{-} + C_2{O}_4^{-2} + H^{+} \stackrel{ }{\to } M{n}^{2+} + C{O}_2 + H_{2}O$

The correct coefficients of the reactants for the balanced equation are

• $Mn{O}_4^{-}$	$C_2{O}_4^{2-}$	H+
  16	5	2

• MnO4-	C2O42-	H+
  2	5	16

• MnO4-	C2O42-	H+
  5	16	2

• MnO4-	C2O42-	H+
  2	16	5

when I^- is oxidised by MnO₄^- in an alkaline medium I^- converts into

• IO₃^-

• I₂

• IO₄^-

• IO^-

For the formation of Cr₂O₃ and Al₂O₃, values of ${∆}_{\mathrm{f}}\mathrm{G}°$ are 540 kJ mol^-1 and -827 kJ mol^-1 respectively. What will be the possibility for reaction of Cr₂O₃ by Al?

• Reduction of Cr₂O₃ by Al will take place

• Oxidation of Cr₂O₃ by Al will take place

• Neither oxidation nor reduction will take place

• Reaction is not feasible

Which of the following statements is incorrect regarding the reaction?

CH₃CHO + [Ag(NH₃)₂]^$\oplus$ + OH^- _$\to$CH₃COO^- + Ag

• The equivalent weight of CH₃CHO is 22

• Three moles of OH^- are required in the above D reaction

• CH₃CHO is an oxidising agent

• Reduction of [Ag(NH₃)₂]^$\oplus$ occurs

The value of n in

Mn${\mathrm{O}}_4^{-}$ + 8H⁺ + ne^- $\to$ Mn²⁺ + 4H₂O is

• 5

• 4

• 2

• 3

When KMnO₄ acts as an oxidising agent and ultimately forms Mn${\mathrm{O}}_4^{2-}$  MnO₂, Mn₂O₃ and Mn²⁺ then the number of electrons, transferred in each case respectively are

• 1, 3, 4, 5

• 3, 2, 1, 4

• 1, 5, 3, 7

• 4, 3, 2, 1