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प्रश्न
Whenever a reaction between an oxidising agent and a reducing agent is carried out, a compound of lower oxidation state is formed if the reducing agent is in excess and a compound of higher oxidation state is formed if the oxidising agent is in excess. Justify this statement giving three illustrations.
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उत्तर
Whenever a reaction between an oxidising agent and a reducing agent is carried out, a compound of lower oxidation state is formed if the reducing agent is in excess and a compound of higher oxidation state is formed if the oxidising agent is in excess. This can be illustrated as follows:
(i) P4 and F2 are reducing and oxidising agents respectively.
If an excess of P4 is treated with F2, then PF3 will be produced, wherein the oxidation number (O.N.) of P is +3.
\[\ce{P4 (excess) + F2 -> ^{+3}PF3}\]
However, if P4 is treated with an excess of F2, then PF5 will be produced, wherein the O.N. of P is +5.
\[\ce{P4 + F2 (excess) -> ^{+5}PF5}\]
(ii) K acts as a reducing agent, whereas O2 is an oxidising agent.
If an excess of K reacts with O2, then K2O will be formed, wherein the O.N. of O is –2.
\[\ce{4K (excess) + O2 -> 2K2 ^{-2}O}\]
However, if K reacts with an excess of O2, then K2O2 will be formed, wherein the O.N. of O is –1.
\[\ce{2K + O2 (excess) -> K2 ^{-1}O2}\]
(iii) C is a reducing agent, while O2 acts as an oxidising agent.
If an excess of C is burnt in the presence of insufficient amount of O2, then CO will be produced, wherein the O.N. of C is +2.
\[\ce{C (excess) + O2 -> ^{+2}CO}\]
On the other hand, if C is burnt in an excess of O2, then CO2 will be produced, wherein the O.N. of C is +4.
\[\ce{C + O2 (excess) -> ^{+4}CO2}\]
संबंधित प्रश्न
The compound AgF2 is an unstable compound. However, if formed, the compound acts as a very strong oxidizing agent. Why?
How do you count for the following observations?
Though alkaline potassium permanganate and acidic potassium permanganate both are used as oxidants, yet in the manufacture of benzoic acid from toluene we use alcoholic potassium permanganate as an oxidant. Why? Write a balanced redox equation for the reaction.
Balance the following redox reactions by ion-electron method:
- \[\ce{MnO-_4 (aq) + I– (aq) → MnO2 (s) + I2(s) (in basic medium)}\]
- \[\ce{MnO-_4 (aq) + SO2 (g) → Mn^{2+} (aq) + HSO-_4 (aq) (in acidic solution)}\]
- \[\ce{H2O2 (aq) + Fe^{2+} (aq) → Fe^{3+} (aq) + H2O (l) (in acidic solution)}\]
- \[\ce{Cr_2O^{2-}_7 + SO2(g) → Cr^{3+} (aq) + SO^{2-}_4 (aq) (in acidic solution)}\]
Balance the following equation in basic medium by ion-electron method and oxidation number methods and identify the oxidising agent and the reducing agent.
\[\ce{P4(s) + OH–(aq) —> PH3(g) + HPO^–_2(aq)}\]
Balance the following equation in basic medium by ion-electron method and oxidation number methods and identify the oxidising agent and the reducing agent.
\[\ce{Cl_2O_{7(g)} + H_2O_{2(aq)} -> ClO-_{2(aq)} + O_{2(g)} + H+_{(aq)}}\]
Chlorine is used to purify drinking water. Excess of chlorine is harmful. The excess of chlorine is removed by treating with sulphur dioxide. Present a balanced equation for this redox change taking place in water.
Balance the following reaction by oxidation number method.
\[\ce{MnO^-_{4(aq)} + Br^-_{ (aq)}->MnO2_{ (s)} + BrO^-_{3(aq)}(basic)}\]
Which of the following is INCORRECT for the following reaction?
\[\ce{2Zn_{(s)} + O2_{(g)} -> 2ZnO_{(s)}}\]
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\[\ce{{x}H2O2_{(aq)} + ClO^-_{4(aq)} -> 2O2_{(g)} + ClO^-_{2(aq)} + {y}H2O_{(l)}}\]
Identify the oxidising agent in the following reaction:
\[\ce{CH4_{(g)} + 2O2_{(g)} -> CO2_{(g)} + 2H2O_{(l)}}\]
Write balanced chemical equation for the following reactions:
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Write balanced chemical equation for the following reactions:
Reaction of liquid hydrazine \[\ce{(N2H4)}\] with chlorate ion \[\ce{(ClO^{-}3)}\] in basic medium produces nitric oxide gas and chloride ion in gaseous state.
Balance the following equations by the oxidation number method.
\[\ce{MnO2 + C2O^{2-}4 -> Mn^{2+} + CO2}\]
Identify the redox reactions out of the following reactions and identify the oxidising and reducing agents in them.
\[\ce{PCl3 (l) + 3H2O (l) -> 3HCl (aq) + H3PO3 (aq)}\]
Identify the redox reactions out of the following reactions and identify the oxidising and reducing agents in them.
\[\ce{4NH3 (g) + 3O2 (g) -> 2N2 (g) + 6H2O (g)}\]
Balance the following ionic equations.
\[\ce{Cr2O^{2-}7 + H^{+} + I- -> Cr^{3+} + I2 + H2O}\]
In \[\ce{Cu^{2+} + Ag -> Cu + Ag^+}\], oxidation half-reaction is:
The weight of CO is required to form Re2(CO)10 will be ______ g, from 2.50 g of Re2O7 according to given reaction
\[\ce{Re2O7 + CO -> Re2(CO)10 + CO2}\]
Atomic weight of Re = 186.2; C = 12 and O = 16.
\[\ce{H2O2 -> 2H^+ + O2 + 2e^-}\]; E0 = −0.68 V.
This equation represents which of the following behaviour of H2O2?
