Chemistry

ANSWER: Given compound is having 8 carbons, and on reaction with chromic acid C is converted back into B, as chromic acid reaction couldn't add any carbon hence both alcohol and acid must contain 4 carbons and it is given in the question that on dehydration C will give but-1-ene so alcohol will be butan-1-ol (C) and acid will be butan-1-oic acid (B) and given reaction will be ester hydrolysis,

 

Since the given compound with molecular formula C₉H₁₀O form a 2,4-DNP derivative and reduce Tollen's reagent, it must be an aldehyde. Since it undergoes cannizzaro reaction, therefore CHO group is directly attached to the benzene ring.

Since on vigorous oxidation, it gives 1,2-benzene dicarboxylic acid, therefore it must be ortho-substituted benzaldehyde. The only o-substituted aromatic aldehyde having molecular formula C₉H₁₀O is o—ethyl benzyldehyde all the reaction can show now be explained on the basis of this structure-

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Option (iii)

Na₆P₆O₁₈

Sodium hexametaphosphate (Na₆P₆O₁₈), commercially called 'calgon', is used to remove hardness from water.

i) Taking two molecules of propanal, one which acts as a nucleophile and the other as an electrophile.

(iii) Taking one molecule each of propanal and butanal in which propanal acts as a nucleophile and butanal acts as an electrophile.

 

This is a multiple choice answer as classified in NCERT Exemplar

Option (i)

Ca²⁺

Water becomes 'hard' when it contains calcium and magnesium salts in the form of hydrogen carbonate, chloride, and sulphate.

This is a multiple choice answer as classified in NCERT Exemplar

Option (iv)

CO (g)+2H₂ (g) → CH₃OH (l)

The reaction shown in equation (iv) shows the synthesis of methanol from water gas.

1. Butane-1,3-diol -

Ethanol react dilute alkali produces 3-hydroxybutanal which on Reduction gives butane-1, 3-diol on reduction.

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Option (ii)

Sulphuric acid

2HSO₄^- (aq) → HO₃SOOSO₃H (aq) → 2HSO₄^- (aq)+2H⁺ (aq) + H₂O₂ (aq)

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Option (iv)

Sodium sulphate and hydrogen peroxide.

Na₂O₂+dil H₂SO₄ → Na₂SO₄ → Na₂SO₄+H₂O₂

This is a multiple choice answer as classified in NCERT Exemplar

Option (iii)

CO (g)+H₂O (g) → CO₂ (g)+H₂ (g)

The production of dihydrogen can be increased by reacting carbon monoxide of syngas mixtures with steam in the presence of iron chromate as catalyst.