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कर्नाटक बोर्ड पी.यू.सी.पीयूसी विज्ञान इयत्ता ११

Assertion (A): Redox couple is the combination of oxidised and reduced form of a substance involved in an oxidation or reduction half cell. Reason (R): In the representation 3+2+EXFe3+/Fe2 - Chemistry

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प्रश्न

Assertion (A): Redox couple is the combination of oxidised and reduced form of a substance involved in an oxidation or reduction half cell.

Reason (R): In the representation \[\ce{E^Θ_{Fe^{3+}/Fe^{2+}}}\] and \[\ce{E^Θ_{Cu^{2+}/Cu}, Fe^{3+}/Fe^{2+}}\] and \[\ce{Cu^{2+}/Cu}\] are redox couples.

पर्याय

  • Both A and R are true and R is the correct explanation of A.

  • Both A and R are true but R is not the correct explanation of A.

  • A is true but R is false.

  • Both A and R are false.

MCQ
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उत्तर

Both A and R are true but R is not the correct explanation of A.

Explanation:

A redox couple is defined as pair of compounds or elements having together the oxidised and reduced forms of it and taking part in an oxidation or reduction half-reaction.

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Oxidation Number - Types of Redox Reactions
  या प्रश्नात किंवा उत्तरात काही त्रुटी आहे का?
पाठ 8: Redox Reactions - Multiple Choice Questions (Type - I) [पृष्ठ ११०]

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एनसीईआरटी एक्झांप्लर Chemistry [English] Class 11
पाठ 8 Redox Reactions
Multiple Choice Questions (Type - I) | Q 32 | पृष्ठ ११०

संबंधित प्रश्‍न

Justify that the following reaction is redox reaction:

\[\ce{CuO(s) + H2(g) → Cu(s) + H2O(g)}\]


Justify that the following reaction is redox reaction:

\[\ce{Fe2O3(s) + 3CO(g) → 2Fe(s) + 3CO2(g)}\]


Fluorine reacts with ice and results in the change: \[\ce{H2O(s) + F2(g) → HF(g) + HOF(g)}\]

Justify that this reaction is a redox reaction.


While sulphur dioxide and hydrogen peroxide can act as oxidising as well as reducing agents in their reactions, ozone and nitric acid act only as oxidants. Why?


How do you count for the following observations?

When concentrated sulphuric acid is added to an inorganic mixture containing chloride, we get colourless pungent-smelling gas HCl, but if the mixture contains bromide then we get red vapour of bromine. Why?


Identify the substance oxidised, reduced, oxidising agent and reducing agent for the following reaction:

\[\ce{2AgBr (s) + C6H6O2(aq) → 2Ag(s) + 2HBr (aq) + C6H4O2(aq)}\]


Identify the substance oxidised, reduced, oxidising agent and reducing agent for the following reaction:

\[\ce{HCHO (l) + 2Cu^{2+}(aq) + 5 OH–(aq) → Cu2O(s) + HCOO–(aq) + 3H2O(l)}\]


Identify the substance oxidised, reduced, oxidising agent and reducing agent for the following reaction:

\[\ce{N2H4(l) + 2H2O2(l) → N2(g) + 4H2O(l)}\]


Identify the substance oxidised, reduced, oxidising agent and reducing agent for the following reaction:

\[\ce{Pb(s) + PbO2(s) + 2H2SO4(aq) → 2PbSO4(s) + 2H2O(l)}\]


Consider the reactions:

\[\ce{2S_2O_3^{(2-)}(aq) + l_2(S) -> S_4O_6^{(2-)}(aq) + 2l-(aq)}\]

\[\ce{S_2O_3^{(2-)}(aq) + 2Br_2(l) + 5H_2O(l) -> 2SO_4^{2-} (aq) + 4Br-(aq) + 10H+ (aq)}\]

Why does the same reductant, thiosulphate react differently with iodine and bromine?


Consider the reactions:

  1. \[\ce{H3PO2(aq) + 4 AgNO3(aq) + 2 H2O(l) → H3PO4(aq) + 4Ag(s) + 4HNO3(aq)}\]
  2. \[\ce{H3PO2(aq) + 2CuSO4(aq) + 2 H2O(l) → H3PO4(aq) + 2Cu(s) + H2SO4(aq)}\]
  3. \[\ce{C6H5CHO(l) + 2[Ag (NH3)2]+(aq) + 3OH–(aq) → C6H5COO–(aq) + 2Ag(s) + 4NH3 (aq) + 2 H2O(l)}\]
  4. \[\ce{C6H5CHO(l) + 2Cu^{2+}(aq) + 5OH–(aq) → No change observed}\]

What inference do you draw about the behaviour of Ag+ and Cu2+ from these reactions?


Arrange the following metals in the order in which they displace each other from the solution of their salts.

Al, Cu, Fe, Mg and Zn.


Identify disproportionation reaction


\[\ce{MnO^{2-}4}\] undergoes disproportionation reaction in acidic medium but \[\ce{MnO^{-}4}\] does not. Give reason.


Why does fluorine not show disporportionation reaction?


Write redox couples involved in the reactions given.

\[\ce{Cu + Zn^{2+} ->Cu^{2+} + Zn}\]


Write redox couples involved in the reactions given.

\[\ce{Mg + Fe^{2+} -> Mg^{2+} + Fe}\]


Write redox couples involved in the reactions given.

\[\ce{Br2 + 2Cl- -> Cl2 + 2Br-}\]


Which of the following statement is CORRECT for the decomposition reaction of KClO3

\[\ce{2KClO3 → 2KCl +3O2}\]


The species given below that does NOT show a disproportionation reaction is ______.


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