CaO + H₂​O → Ca(OH)₂

Oxidation number doesn’t change so its not a redox reaction.

Reduction potential of D is minimum i.e. −0.402 V. Thus oxidation potential of D is maximum i.e. to +0.402 V. D can oxidise itself and reduce other. The aqueous solution A will be present in its ionic form and can be reduced by D as its reduction potential is higher than D.

In F₂O

⇒ 2  ×  (−1) + x = 0

⇒ x = +2

Given Reduction Potential: M → +2.46V N → +1.13V O → −3.13V We know that the electrode which has more reduction potential is a good oxidizing agent and has least reducing power. While the electrode which has less reduction potential, it has more reducing power. Therefore, Order of reducing power is: – O > M > N

The reaction 4Fe + 3O2 + 6H2O → 4Fe(OH)3 takes place in the acidic medium as we see and Fe is converted to Fe⁺².

Alkalis are compounds that have OH^- ions in them, i.e, they liberate hydroxide ions on dissociation.

The alkalis are generally bases and they react with acids to neutralize the solution to produce water.

The hydroxyl ions are basically consuming the protons or H⁺ to form water.

Thus, the reaction medium doesn't have any hydronium ion left and the oxidation reaction of iron cannot proceed.

Hence, we can say that an alkaline medium inhibits the rusting of iron, because of the non-availability of H+ ions which reduces oxidation of Fe to Fe+2 ions.

In alkaline medium the reduction of KMnO4 with KI will takes place as

2 KMnO₄ + H₂O → 2 KOH + 2 MnO₂ KI + 3[O] → KIO₃

Hence the overall reaction is KI + 2KMnO₄ + H₂O → KIO₃ + 2 KOH + 2 MnO₂

So, one mole of KI will reduced two moles of KMnO₄

Autoxidation is any oxidation that occurs in presence of oxygen. The term is usually used to describe the degradation of organic compounds in air (as a source of oxygen). Autoxidation produces hydroperoxides and cyclic organic peroxides. These species can react further to form many products. The process is relevant to many phenomena including aging, paint, and spoilage of foods, degradation of petrochemicals, and the industrial production of chemicals. Autoxidation is important because it is a useful reaction for converting compounds to oxygenated derivatives, and also because it occurs in situations where it is not desired (as in the destructive cracking of the rubber in automobile tires or in rancidification). Water automatically gets oxidised to hydrogen peroxide.

Oxidation state of oxygen family Oxygen shows -2, +2 and -1

Oxidation states other elements show +2, +4 and +6 oxidation states

In H₂S, the oxidation state of S is -2. Oxidation state of S lie between -2 to +6.

Option (A)

S2 molecule is paramagnetic.

This option is incorrect.

Option (B)

The vapour at 200° C consists mostly of S8 rings.

This option is incorrect.

Option (C)

At 600° C the gas mainly consists of S₂ molecules.

This option is incorrect.

Option (D)

The oxidation state of sulphur is never less than +4 in its compounds.

This option is correct.

A single bond between two atoms is always considered as sigma bond.

A double bond between two atoms is always considered as one sigma and one pi bond

A triple bond between two atoms is always considered as one sigma bond and two pi bonds.

So according to the given structure CaC₂ (Calcium carbide) has 1 sigma and 2 pi bonds

Oxidation process Involves:-

(i) Addition of O₂ ​or electronegative element
(ii) Removal of H/ electropositive element
(iii) Loss of electrons
(iv) Increase in oxidation number