Match the structures of the compounds given in Column I with the name of the compounds given in Column II.
(i — » d), (ii — » c), (iii —> f), (iv —> a), (v — » g), (vi — » b)
(i) Cresols are organic compounds which are methyl phenols. There are three forms of cresol: o-cresol, p-cresol and w-cresol.
(ii) Catechol is also known as pyrocatechol. Its IUPAC name is 1, 2-dihydrobenzene. It is used in the production of pesticides, perfumes and pharmaceuticals.
(iii) Its IUPAC name is 1, 3-dihydroxybenzene. Resorcinol is used to treat acne, seborrheic dermatitis and other skin disorder.
(iv) Hydroquinone is also known as quinol. Its IUPAC name is 1, 4-dihydroxybenzene. Itisawhite granularsolid.lt isagoodreducing agent.
(v) Anisole or methoxy benzene, is a colourless liquid with a smell reminiscent of anise seed.
(vi) Phenetole is an organic compound. It is also known as ethylphenyl ether. It is volatile in nature and its vapour are explosive in nature.
Assertion (A): Phenol forms 2,4, 6-tribromophenol on treatment with Br2 in carbon disulphide at 273 K.
Reason (R): Bromine polarizes in carbon disulphide.
Assertion (A): Phenols give o-nitrophenol and p-nitrophenol on nitration with cone. HNO3 and H2SO4 mixture.
Reason (R): -OH group in phenol is o-,p-directing.
Write the names of reagents and equations for the preparation of the following ethers by Williamson's synthesis:
(i)1-Propoxypropane
(ii)Ethoxybenzene
(iii)2-Methoxy-2-methylpropane
(iv)1-Methoxyethane
Ethers can be prepared by Williamson's synthesis in which an alkyl halide is reacted with sodium alkoxide. Di-tert-butyl ether cannot be prepared by this method. Explain.
While separating a mixture of ortho and para nitrophenols by steam distillation, name the isomer which will be steam volatile. Give reason.
Explain how does the – OH group attached to a carbon of benzene ring activate it towards electrophilic substitution?
Write the equation of the reaction of hydrogen iodide with (i)1-propoxypropane (ii)methoxybenzene, and (iii)benzyl ethyl ether
Explain the fact that in aryl alkyl ethers (i) the alkoxy group activates the benzene ring towards electrophilic substitution and (ii) it directs the incoming substituents to ortho and para positions in benzene ring.
Arrange the following compounds in increasing order of acidity and give a suitable explanation:
Phenol, o-Nitrophenol, o-Cresol
Give structures of the products you would expect when each of the following alcohol reacts with (a)HCl-ZnCl2 (b)HBrand (c) SOCl2
(i)Butan-1-ol
(ii)2-Methylbutan-2-ol
When phenol is treated with bromine water, white precipitate is obtained. Give the structure and the name of the compound formed.
Write the structures of the isomers of alcohols with molecular formula C4H10O. Which one of these isomers exhibits optical activity?
Match the starting materials given in Column I with the products formed by these (Column II) in the reaction with HI.
Assertion (A): o-Nitrophenol is less soluble in water than the m- and p-isomers.
Reason (R): m-Nitrophenol and p-Nitrophenol exists as associated molecules.
Predict the major product of acid catalysed dehydration of
(i) 1-nicthylcyclohcxanoland
(ii) butan-1-ol
Which of the following is an appropriate set of reactants for the preparation of l-methoxy-4- nitrobenzene and why?
Alcohols are comparatively more soluble in water than hydrocarbons of comparable molecular masses. Explain this fact.
You are given benzene, cone. H2S04and NaOH. Write the equations for the preparation of phenol using these reagents.
Illustrate with examples the limitations of Willamson synthesis for the preparation of certain types of ethers.
Preparation of ethers by acid dehydration of secondary or tertiary alcohols is not a suitable method.Give reason.
Which of the following are used to convert RCHO into RCH2OH?
(a) H2/Pd
(b) LiAlH4
(c) NaBH4
(d) Reaction with RMgX followed by hydrolysis
Phenol can be distinguished from ethanol by the reactions with ………….
(a) Br2/water (b) Na
(c) Neutral FeCl3 (d) All of these
Why is the reactivity of all three classes of alcohols with cone. HCl and ZnCl2 (Lucas reagent) different?
Explain why alcohols and ethers of comparable molecular mass have different boiling points.
Assertion (A): Like bromination of benzene, bromination of phenol is also carried out in the presence of Lewis acid.
Reason (R): Lewis acid polarizes the bromine molecule.
Assertion (A): Ethanol is a weaker acid than phenol.
Reason (R): Sodium ethoxide may be prepared by the reaction of ethanol with aqueous NaOH.
Write the equations involved in the following reactions:
(i) Reimer-Tiemann reaction
(ii) Kolbe's reaction
