Class 12 Chemistry - Chapter Alcohols Phenols and Ethers NCERT Solutions | Show how will you synthesize: (i) 1-p

Explain the following with an example.

(i) Kolbe's reaction.

(ii) Reimer-Tiemann reaction.

(iii) Williamson ether synthesis.

(iv) Unsymmetrical ether.

How are the following conversions carried out?

(i) Propene → Propan-2-ol

(ii) Benzyl chloride → Benzyl alcohol

(iii) Ethyl magnesium chloride → Propan-1-ol.

(iv) Methyl magnesium bromide → 2-Methylpropan-2-ol.

Write the mechanism of acid-catalysed dehydration of ethanol to yield ethene.

Give the equations of reactions for the preparation of phenol from cumene.

Write equations of the following reactions:

(i) Friedel-Crafts reaction-alkylation of anisole.

(ii) Nitration of anisole.

(iii) Bromination of anisole in ethanoic acid medium.

(iv) Friedel-Craft's acetylation of anisole.

Explain why is ortho nitrophenol more acidic than ortho methoxyphenol?

Give two reactions that show the acidic nature of phenol. Compare acidity of phenol with that of ethanol.

Show how are the following alcohols prepared by the reaction of a suitable

Grignard reagent on methanal?

(i)

(ii)

Write the reactions of Williamson synthesis of 2-ethoxy-3-methylpentane starting from ethanol and 3-methylpentan-2-ol.

What is meant by hydroboration-oxidation reaction? Illustrate it with an example.

For the reaction R → P, the concentration of a reactant changes from 0.03 M to 0.02 M in 25 minutes. Calculate the average rate of reaction using units of time both in minutes and seconds.

Write the formulas for the following coordination compounds:

(i) Tetraamminediaquacobalt (III) chloride

(ii) Potassium tetracyanonickelate(II)

(iii) Tris(ethane-1,2-diamine) chromium(III) chloride

(iv) Amminebromidochloridonitrito-N-platinate(II)

(v) Dichloridobis(ethane-1,2-diamine)platinum(IV) nitrate

(vi) Iron(III) hexacyanoferrate(II)

(i) Write structures of different isomeric amines corresponding to the molecular formula, C4H11N

(ii) Write IUPAC names of all the isomers.

(iii) What type of isomerism is exhibited by different pairs of amines?

Why are solids rigid?

Write any two characteristics of Chemisorption.

Write the structures of the following compounds.

(i) α-Methoxypropionaldehyde

(ii) 3-Hydroxybutanal

(iii) 2-Hydroxycyclopentane carbaldehyde

(iv) 4-Oxopentanal

(v) Di-sec-butyl ketone

(vi) 4-Fluoroacetophenone

Which of the ores mentioned in Table 6.1 can be concentrated by magnetic separation method?

Why are pentahalides more covalent than trihalides?

Silver atom has completely filled d orbitals (4d10) in its ground state. How can you say that it is a transition element?

Glucose or sucrose are soluble in water but cyclohexane or benzene (simple six membered ring compounds) are insoluble in water. Explain.

If the density of some lake water is 1.25 g mL^-1 and contains 92 g of Na⁺ ions per kg of water, calculate the molality of Na⁺ ions in the lake.

Is ( NH — CHR — CO )_n a homopolymer or copolymer?

How will you prepare the following compounds from benzene? You may use any inorganic reagent and any organic reagent having not more than one carbon atom

(i) Methyl benzoate             (ii) m-Nitrobenzoic acid

(iii) p-Nitrobenzoic acid        (iv) Phenylacetic acid

(v) p-Nitrobenzaldehyde.

Which compound in each of the following pairs will react faster in S_N2 reaction with OH^-?

(i) CH₃Br or CH₃I

(ii) (CH₃)₃CCl or CH₃Cl

Name the members of the lanthanoid series which exhibit +4 oxidation state and those which exhibit +2 oxidation state. Try to correlate this type of behavior with the electronic configurations of these elements.

Why are vitamin A and vitamin C essential to us? Give their important sources.

Why are cimetidine and ranitidine better antacids than sodium hydrogencarbonate or magnesium or aluminium hydroxide ?

Give examples and suggest reasons for the following features of the transition metal chemistry:

(i)The lowest oxide of transition metal is basic, the highest is amphoteric/acidic.

(ii)A transition metal exhibits highest oxidation state in oxides and fluorides.

(iii) The highest oxidation state is exhibited in oxoanions of a metal.

How many geometrical isomers are possible in the following coordination entities?

(i) [Cr(C₂O₄)₃]^3-

(ii) [Co(NH₃)₃Cl₃]

Why is the extraction of copper from pyrites more difficult than that from its oxide ore through reduction?