Chemistry · Class 12 Science
Ch 11Hydroxy Compounds and Ethers — Class 12 Chemistry, concept-first.
You already know from Class XI that hydrolysing an alkyl halide gives an alcohol -- an organic compound carrying the hydroxyl (-OH) functional group. That single functional group turns out to be everywhere in biology and industry: cholesterol (cholesteryl alcohol) is a core component of your cell membranes, retinol (th…
Key concepts
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Distinguishing Alcohols — Lucas Test and Victor Meyer's Test
The Lucas test (conc. HCl + anhydrous ZnCl2) reads REACTION SPEED: a tertiary alcohol turns turbid immediately, a secondary one within about 10 minutes, and a primary one only on heating -- tracking how readily each form…
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Chapter contents
The NCERT structure, section by section. Open a section to see its questions, then read the concept-first solution.
Introduction
You already know from Class XI that hydrolysing an alkyl halide gives an alcohol -- an organic compound carrying the hydroxyl (-OH) functional group.
Classification of Alcohols
Alcohols are organic compounds bearing a hydroxyl (-OH) functional group. Based on the NUMBER of -OH groups, alcohols are classed as monohydric (one -OH, e.g.
IUPAC Nomenclature of Alcohols
IUPAC naming of an alcohol follows four steps: (1) select the longest continuous carbon chain that contains the -OH group as the root chain; (2) number the chain so the -OH-bearing carbon gets the low…
Structure of the Functional Group of Alcohol
The -O-H group of an alcohol attached to an sp3-hybridised carbon has the same bent ('V'-shaped) geometry as the -O-H of water.
Preparation of Alcohols
Alcohols are prepared industrially and in the laboratory from several different starting materials: alkyl halides (by nucleophilic substitution), alkenes (by acid-catalysed hydration or by hydroborati…
Preparation of Alcohols from Alkyl Halides
Alkyl halides, on heating with dilute aqueous NaOH, undergo nucleophilic substitution to give alcohols: R-X + NaOH(aq), heat, gives R-OH + NaX.
Preparation of Alcohols from Alkenes (Acid-Catalysed Hydration)
Water adds across the C=C double bond of an alkene in the presence of concentrated sulphuric acid to give an alcohol, following Markovnikov's rule -- the -OH group ends up on the more substituted carb…
Preparation of Alcohols Using Grignard Reagent
A Grignard reagent (R-MgX) adds as a nucleophile to the electrophilic carbonyl carbon of an aldehyde or ketone in dry ether; acid hydrolysis of the resulting magnesium alkoxide then liberates the alco…
Preparation of Alcohols by Hydroboration-Oxidation
Diborane (B2H6) adds across an alkene's double bond to form a trialkylborane, which on treatment with alkaline hydrogen peroxide (H2O2/NaOH) gives an alcohol; overall this is a hydration of the alkene…
Preparation of Alcohols by Reduction of Carbonyl Compounds
Aldehydes and ketones are reduced to alcohols by lithium aluminium hydride (LiAlH4) in a solvent such as tetrahydrofuran (THF), followed by hydrolysis; unlike Raney nickel or Na-Hg/H2O, LiAlH4 does NO…
Preparation of Glycol
Ethylene glycol (ethane-1,2-diol) is made by hydroxylating ethene with cold, dilute alkaline potassium permanganate solution (Baeyer's reagent): CH2=CH2 + H2O + [O] (cold alkaline KMnO4) gives HO-CH2-…
Preparation of Glycerol
Glycerol (propane-1,2,3-triol) occurs naturally in fats and oils as its fatty-acid triesters (triglycerides, e.g. glyceryl tripalmitate).
Distinguishing Primary, Secondary and Tertiary Alcohols
Because primary, secondary and tertiary alcohols show different reactivity patterns, two classical wet-chemistry tests distinguish between them without needing spectroscopy: the Lucas test (based on d…
Lucas Test
Lucas reagent is a mixture of concentrated HCl and anhydrous ZnCl2 (ZnCl2 acts as a Lewis-acid catalyst that helps ionise the alcohol).
Victor Meyer's Test
This three-step test converts an alcohol into a nitroalkane and reads its colour with alkali. Step 1: the alcohol is converted to an alkyl iodide with I2/red phosphorus.
Physical Properties of Alcohols
Lower alcohols are colourless liquids; higher members are waxy solids. Alcohols have markedly higher boiling points than alkanes, aldehydes or ethers of comparable molar mass, because of intermolecula…
Chemical Properties of Alcohols
The -OH group of an alcohol takes part in four broad reaction families covered here: nucleophilic substitution (of the whole -OH, converting it to a leaving group first), elimination (dehydration to a…
Nucleophilic Substitution Reactions of Alcohols
Hydroxide is a poor leaving group, so before any substitution the alcohol's -OH is first activated -- protonated by an acid to the good leaving group -OH2+, which a nucleophile such as Br- can then di…
Elimination Reactions of Alcohols (Dehydration) and Saytzeff's Rule
Heating an alcohol with a dehydrating agent (concentrated H2SO4, phosphoric acid, anhydrous ZnCl2 or alumina) eliminates -OH and an adjacent -H to form a C=C double bond.
Oxidation of Alcohols
Oxidation of alcohols, typically with acidified sodium dichromate (Na2Cr2O7), gives carbonyl compounds.
Esterification of Alcohols
In the presence of an acid catalyst, an alcohol reacts with a carboxylic acid to form an ester and water (Fischer esterification) -- e.g.
Reactions of Glycol
Ethylene glycol (ethane-1,2-diol) carries two primary -OH groups and shows the general reactions of alcohols, doubled. With metallic sodium it forms mono- then disodium glycolate.
Reactions of Glycerol
NITRATION: glycerol reacts with concentrated nitric acid (in concentrated H2SO4) to form 1,2,3-trinitroxypropane, better known as nitroglycerine (TNG), the explosive Alfred Nobel stabilised into dynam…
Uses of Alcohols
Methanol is used as an industrial solvent for paints, varnishes, shellac, gums and cement, and as a starting material for dyes, drugs, perfumes and formaldehyde manufacture.
Acidity of Alcohols
By the Bronsted definition, an acid is a proton donor. Alcohols are only weakly acidic, comparable to water: water's Ka is about 1.8x10^-16, while alcohols' Ka values fall in the range 10^-16 to 10^-1…
Acidity of Phenol
Phenol is considerably more acidic than aliphatic alcohols: unlike an alcohol, phenol reacts with aqueous NaOH to form sodium phenoxide, C6H5-OH + NaOH gives C6H5-O-Na+ + H2O.
Classification and Nomenclature of Phenols
Phenols are organic compounds in which an -OH group is attached directly to a benzene ring, on a carbon that is sp2-hybridised.
Preparation of Phenols
Phenol is manufactured or prepared in the laboratory from four different starting materials: haloarenes (Dow's process), benzenesulphonic acid (alkali fusion), aniline (via diazotisation), and cumene…
Preparation of Phenol -- Dow's Process
In Dow's process, chlorobenzene is hydrolysed with 6-8% NaOH at high pressure (about 300 bar) and 633 K in a closed vessel to give sodium phenoxide, which on acidification with dilute HCl liberates ph…
Preparation of Phenol from Benzene Sulphonic Acid
Benzene is sulphonated with oleum (fuming sulphuric acid, H2SO4 with dissolved SO3) to give benzenesulphonic acid; heating this with molten (solid, not aqueous) NaOH at 623 K gives sodium phenoxide, a…
Preparation of Phenol from Aniline
Aniline is diazotised with nitrous acid (generated in situ from NaNO2 + HCl) at the low temperature of 273-278 K (a diazonium salt decomposes above about 283 K) to give benzenediazonium chloride; warm…
Preparation of Phenol from Cumene
The industrial cumene process starts by Friedel-Crafts alkylation: benzene and propene, heated at 523 K in a closed vessel with H3PO4 catalyst, give cumene (isopropylbenzene).
Physical Properties of Phenol
Phenol is a colourless, needle-shaped, hygroscopic, corrosive and poisonous crystalline solid that turns pink on exposure to air and light (due to slow aerial oxidation).
Chemical Reactions of the -OH Group of Phenol
Phenol's -OH group participates in six characteristic reactions, several with no true parallel in simple alcohol chemistry: reduction of the whole ring with zinc dust, conversion to an amine with ammo…
Reaction of Phenol with Zinc Dust
Heating phenol with zinc dust reduces it to benzene, eliminating the aromatic -OH group entirely: C6H5-OH + Zn (heat) gives C6H6 + ZnO.
Reaction of Phenol with Ammonia
Phenol heated with ammonia in the presence of anhydrous ZnCl2 undergoes nucleophilic replacement of -OH by -NH2 to give aniline: C6H5-OH + NH3 (anhydrous ZnCl2) gives C6H5-NH2 + H2O.
Formation of Esters -- Schotten-Baumann Reaction
Phenol reacts with acid chlorides (in the presence of NaOH/pyridine) to give esters; this acetylation/benzoylation of phenol is called the Schotten-Baumann reaction.
Formation of Ethers from Phenol -- Williamson Synthesis
An alkaline solution of phenol (i.e. the phenoxide ion) undergoes nucleophilic substitution on an alkyl halide to form a phenyl ether -- this is the Williamson ether synthesis applied to phenol.
Oxidation of Phenol
Phenol is oxidised by air, or by acidified K2Cr2O7 in concentrated H2SO4, to 1,4-benzoquinone -- the -OH-bearing ring carbon and the para carbon both become carbonyl (=O) carbons, breaking the ring's…
Reduction of Phenol
Catalytic hydrogenation of phenol (H2, Ni catalyst, about 433 K/160 degrees C) reduces the entire aromatic ring, giving cyclohexanol: C6H5-OH + 3 H2 (Ni, heat) gives cyclohexanol.
Electrophilic Aromatic Substitution Reactions of Phenol
The -OH group directly attached to phenol's ring is a strong ACTIVATING, ortho/para-DIRECTING group (it donates electron density into the ring by resonance), so phenol undergoes electrophilic aromatic…
Nitrosation and Nitration of Phenol
NITROSATION: phenol reacts readily with nitrous acid (HNO2) at low temperature (278 K) to give p-nitrosophenol as the major product.
Sulphonation and Halogenation of Phenol
SULPHONATION: phenol with concentrated H2SO4 at 280 K gives mainly o-phenolsulphonic acid (the kinetic product), while carrying out the same reaction at 373 K gives mainly p-phenolsulphonic acid (the…
Kolbe's Reaction
In Kolbe's (or Kolbe-Schmitt) reaction, phenol is first converted to sodium phenoxide (with NaOH), which -- being more electron-rich and so more reactive toward electrophiles than phenol itself -- rea…
Riemer-Tiemann Reaction
Treating phenol with chloroform (CHCl3) and aqueous NaOH introduces a -CHO group specifically at the ortho position, via a substituted benzal chloride (dichlorocarbene-derived) intermediate that is su…
Phthalein Reaction and Coupling Reaction
PHTHALEIN REACTION: heating phenol with phthalic anhydride in the presence of concentrated H2SO4 gives phenolphthalein, the familiar acid-base indicator, via double electrophilic attack of two phenol…
Distinguishing Alcohols and Phenols
Three simple tests tell an aromatic phenol apart from a simple aliphatic alcohol such as ethanol. (1) Phenol couples with benzenediazonium chloride to give a red-orange azo dye; ethanol gives no such…
Uses of Phenol
About half of world phenol production goes into making phenol-formaldehyde resin (Bakelite), an early and still-important thermosetting plastic.
Classification and Structure of Ethers
Ethers are organic compounds in which an oxygen atom bridges two alkyl and/or aryl groups (general form R-O-R'); they can be regarded as hydrocarbon derivatives in which one hydrogen has been replaced…
IUPAC Nomenclature of Ethers
An ether is IUPAC-named by treating the smaller alkyl/aryl group (with its oxygen) as an ALKOXY or ARYLOXY substituent prefix on the parent chain formed by the larger group.
Preparation of Ethers
Ethers are prepared by three principal routes: intermolecular dehydration of an alcohol (best for SIMPLE ethers), the Williamson ether synthesis from an alkoxide and an alkyl halide (the general, most…
Preparation of Ethers by Intermolecular Dehydration of Alcohols
Two moles of an alcohol, heated with concentrated H2SO4, can either eliminate (dehydrate to an alkene, favoured at higher temperature) or undergo intermolecular substitution to form an ether (favoured…
Williamson Ether Synthesis
Heating an alkyl halide with an alcoholic solution of a sodium alkoxide gives the corresponding ether by an SN2 mechanism: CH3-ONa + Br-C2H5 (heat) gives CH3-O-C2H5 + NaBr (methoxyethane).
Methylation of Alcohols (Diazomethane Method)
An alcohol reacted with diazomethane (CH2N2) in the presence of a catalyst such as fluoroboric acid (HBF4) gives the corresponding methyl ether, releasing nitrogen gas: CH3-CH2-OH + CH2N2 (HBF4, heat)…
Physical Properties of Ethers
Ethers are polar molecules: an ether's dipole moment is the vector sum of its two polar C-O bonds, with a further contribution from oxygen's two lone pairs -- diethyl ether, for instance, has a dipole…
Chemical Properties of Ethers
The ether C-O bond is normally quite unreactive, but it does undergo three characteristic reaction types: nucleophilic substitution/cleavage by strong hydrohalic acids, slow autooxidation by atmospher…
Nucleophilic Substitution Reactions of Ethers
Ethers are cleaved by the strong hydrohalic acids HBr or HI (HI is the more reactive of the two): methoxyethane + HI (heat) gives iodomethane + ethanol; methoxybenzene (anisole) + HI gives phenol + io…
Autooxidation of Ethers
On storage in contact with atmospheric oxygen, ethers slowly and spontaneously oxidise -- a process called AUTOOXIDATION -- to form hydroperoxides and dialkyl peroxides (e.g.
Aromatic Electrophilic Substitution Reactions of Ethers
The alkoxy group (-OR) on an aromatic ether is, like a phenol's -OH, an activating and ortho/para-directing substituent, so aromatic ethers such as anisole undergo electrophilic aromatic substitution…
Uses of Ethers
Diethyl ether was historically used as a surgical general anaesthetic; today it survives mainly as a good, widely used solvent for organic reactions and extractions, as a volatile starting fluid for d…
EVALUATION
47 QThe EVALUATION section closes the unit with two question sets. 'Choose the Best Answer' (22 MCQs) tests identification of alcohols/phenols/ethers from reaction clues, naming, acidity comparisons, and…
+−Choose the Best Answer22 questions
- Q1An alcohol (X) gives blue colour in Victor Meyer's test, and 3.7 g of X when treated with metallic sodium liberates 560 mL of hydrogen at 27…Free
- Q2Which of the following compounds on reaction with methylmagnesium bromide will give a tertiary alcohol? a) benzaldehyde b) propanoic acid c)…Free
- Q3Pent-1-ene, CH3-CH2-CH2-CH=CH2, is treated with (i) BH3/THF (ii) H2O2/OH- to give 'X'. X is a) CH3-CH2-CH2-CH2-CH2-OH b) CH3-CH(OH)-CH2-CH2-…Free
- Q4In the reaction sequence, Ethene --HOCl--> A --X--> ethane-1,2-diol, A and X respectively are a) Chloroethane and NaOH b) ethanol and H2SO4…Preview
- Q5Which one of the following is the strongest acid? a) 2-nitrophenol b) 4-chlorophenol c) 4-nitrophenol d) 3-nitrophenolPreview
- Q6Cyclohexylmethanol (cyclohexyl-CH2-OH) on treatment with conc. H2SO4 predominantly gives a) methylenecyclohexane (an exocyclic C=CH2) b) 3-m…Preview
- Q7Carbolic acid is a) Phenol b) Picric acid c) benzoic acid d) phenylacetic acidPreview
- Q8Which one of the following will react with phenol to give salicylaldehyde after hydrolysis? a) Dichloromethane b) trichloroethane c) trichlo…Preview
- Q9(CH3)3C-CH(OH)-CH3 --Conc. H2SO4--> X (major product). X is (as printed in the textbook, options (c) and (d) are the same structure) a) (CH3…Preview
- Q10The correct IUPAC name of the compound H3C-CH(Cl)-CH(CH3)-CH(CH3)-CH2-OH is a) 4-chloro-2,3-dimethylpentan-1-ol b) 2,3-dimethyl-4-chloropent…Preview
- Q11Assertion: Phenol is more acidic than ethanol. Reason: Phenoxide ion is resonance stabilized. a) both assertion and reason are true and reas…Preview
- Q12In the reaction: Ethanol --PCl5--> X --alc.KOH--> Y --H2SO4/H2O, 298K--> Z. The 'Z' is a) ethane b) ethoxyethane c) ethylbisulphite d) ethan…Preview
- Q13The reaction: Cyclopentanol --NaH--> cyclopentyl sodium alkoxide (ONa) --CH3-I--> methoxycyclopentane. This can be classified as a) dehydrat…Preview
- Q14Isopropylbenzene (cumene) on air oxidation in the presence of dilute acid gives a) C6H5COOH b) C6H5COCH3 c) C6H5COC6H5 d) C6H5-OHPreview
- Q15Assertion: Phenol is more reactive than benzene towards electrophilic substitution reaction. Reason: In the case of phenol, the intermediate…Preview
- Q16HO-CH2-CH2-OH on heating with periodic acid gives a) methanoic acid b) Glyoxal c) methanal d) CO2Preview
- Q17Which of the following compounds can be used as antifreeze in automobile radiators? a) methanol b) ethanol c) Neopentyl alcohol d) ethane-1,…Preview
- Q18The reaction of catechol (benzene-1,2-diol) with (i) NaOH (ii) CH2I2 to give the cyclic product 1,3-benzodioxole (a -O-CH2-O- bridge across…Preview
- Q19One mole of an organic compound (A), molecular formula C3H8O, reacts completely with two moles of HI to form X and Y. When Y is boiled with…Preview
- Q20Among the following ethers, which one will produce methyl alcohol on treatment with hot HI? a) (CH3)3C-O-CH3 b) (CH3)2CH-CH2-O-CH3 c) CH3-(C…Preview
- Q21Williamson synthesis for preparing dimethyl ether is a/an a) SN1 reaction b) SN2 reaction c) electrophilic addition d) electrophilic substit…Preview
- Q22On reacting with neutral ferric chloride solution, phenol gives a) red colour b) violet colour c) dark green colour d) no colourationPreview
+−Write Brief Answer25 questions
- Q1Identify the product(s) formed when 1-methoxypropane is heated with excess HI. Name the mechanism involved in the reaction.Free
- Q2Draw the major product formed when 1-ethoxyprop-1-ene (CH3-CH=CH-O-C2H5) is heated with one equivalent of HI.Free
- Q3Suggest a suitable reagent to prepare a secondary alcohol with two identical alkyl groups using a Grignard reagent.Free
- Q4What is the major product obtained when two moles of ethylmagnesium bromide are treated with methyl benzoate, followed by acid hydrolysis?Preview
- Q5Predict the major product when 2-methylbut-2-ene is converted into an alcohol by each of the following methods: (i) Acid-catalysed hydration…Preview
- Q6Arrange the following in increasing order of their boiling point and give a reason for your ordering: (i) Butan-2-ol, Butan-1-ol, 2-methylpr…Preview
- Q7Can we use nucleophiles such as NH3, CH3O- for the nucleophilic substitution of alcohols?Preview
- Q8Is it possible to oxidise t-butyl alcohol using acidified dichromate to form a carbonyl compound?Preview
- Q9What happens when 1-phenylethanol is treated with acidified KMnO4?Preview
- Q10Write the mechanism of acid-catalysed dehydration of ethanol to give ethene.Preview
- Q11How is phenol prepared from (i) chlorobenzene (ii) isopropylbenzene (cumene)?Preview
- Q12Explain Kolbe's reaction.Preview
- Q13Write the chemical equation for the Williamson synthesis of 2-ethoxy-2-methylpentane starting from ethanol and 2-methylpentan-2-ol.Preview
- Q14Write the structure of the aldehyde, carboxylic acid and ester that would yield 4-methylpent-2-en-1-ol on reduction with LiAlH4.Preview
- Q15What is metamerism? Give the structure and IUPAC name of the metamers of 2-methoxypropane.Preview
- Q16How are the following conversions effected? (i) benzyl chloride to benzyl alcohol (ii) benzyl alcohol to benzoic acid.Preview
- Q17Complete the following reactions: (i) CH3-CH2-OH --PBr3--> A --aq.NaOH--> B --Na--> C (ii) C6H5-OH --Zn dust--> A --CH3Cl/Anhydrous AlCl3-->…Preview
- Q180.44 g of a monohydric alcohol, when added to methylmagnesium iodide in ether, liberates 112 cm3 of methane at STP. With PCC, the same alcoh…Preview
- Q19Complete the following reactions: (i) Phenol --C6H5COCl/OH---> A --Nitration--> B (major product) (ii) C6H5-CH2-CH(OH)-CH(CH3)2 --Conc. H2SO…Preview
- Q20Phenol is distilled with Zn dust followed by Friedel-Crafts alkylation with propyl chloride to give a compound A; A on oxidation gives B. Id…Preview
- Q21CH3MgBr + cyclohexanone --H3O+--> A --HBr--> B --Mg/ether--> C --HCHO/H3O+--> D. Identify A, B, C, D and write the complete equations.Preview
- Q22What will be the products X and A for the following reaction: acetyl chloride --(i) CH3MgBr (ii) H3O+--> X --acidified K2Cr2O7--> A?Preview
- Q23How will you convert acetylene into n-butyl alcohol?Preview
- Q24Predict the products A, B, X and Y in the following sequence of reactions: butan-2-ol --SOCl2--> A --Mg/ether--> B; butan-2-ol --Cu/573K-->…Preview
- Q253,3-dimethylbutan-2-ol on treatment with conc. H2SO4 gives tetramethylethylene (2,3-dimethylbut-2-ene) as the major product. Suggest a suita…Preview
Sample & Board Papers
Sample papers and previous-year board questions for this subject.
+−Show 29 questionsHide questions29 questions
- Q1The reaction of ethylene glycol with $PI_3$ gives : (a) $ICH_2-CH_2I$ (b) $CH_2=CH_2$ (c) $CH_2=CHI$ (d) $ICH=CHI$Preview
- Q2The isomerism exhibited by $C_2H_5OC_2H_5$ and $CH_3-O-CH(CH_3)-CH_3$ is : (a) functional (b) metamerism (c) position (d) chainPreview
- Q3The intramolecular hydrogen bonding is present in : (a) o-nitrophenol (b) m-nitrophenol (c) p-nitrophenol (d) phenolPreview
- Q4With a mixture of Conc. $HNO_3$ and Conc. $H_2SO_4$, Anisole gives : (a) ortho nitro anisole (b) para nitro anisole (c) ortho and para nitro…Preview
- Q5Alcohols cannot be used as a solvent for Grignard reagent. Give reason.Preview
- Q6How will you prepare benzyl alcohol from toluene ?Preview
- Q7Give any five differences between aromatic and aliphatic ethers.Preview
- Q8(a) Describe the conformations of cyclohexanol. Comment on their stability. (b) How are the following conversions carried out ? (i) Salicyli…Preview
- Q9(a) An organic compound (A) of molecular formula $C_6H_6O$, gives violet colour with neutral ferric chloride. Compound (A) when refluxed wit…Preview
- Q10The intramolecular hydrogen bonding in compounds leads to : (a) less boiling point and high solubility in water. (b) less boiling point and…Preview
- Q11The formation of oxonium salt when ether reacts with strong mineral acids is called : (a) deprotonation (b) electronation (c) dehydration (d…Preview
- Q12A compound that undergoes bromination easily is : (a) phenol (b) benzoic acid (c) toluene (d) benzenePreview
- Q13Which one of the following is a simple ether ? (a) $C_2H_5-O-CH_3$ (b) $C_3H_7-O-C_2H_5$ (c) $CH_3-O-C_6H_5$ (d) $C_2H_5-O-C_2H_5$Preview
- Q14Complete the reaction and write the name of the product. $CH_3CH_2OH \xrightarrow[620K]{Al_2O_3} ?$Preview
- Q15Give three methods of preparation of anisole.Preview
- Q16(a) An organic compound (A) of molecular formula $C_6H_6O$ gives violet colour with neutral ferric chloride. Compound (A) when heated with z…Preview
- Q17When ethyl iodide is treated with dry silver oxide it forms : (a) Diethyl ether (b) Ethyl methyl ether (c) Ethyl alcohol (d) Silver ethoxidePreview
- Q18From which of the following one, tertiary butyl alcohol is obtained by the action of methyl magnesium iodide ? (a) $CH_3CHO$ (b) $CO_2$ (c)…Preview
- Q19(a) (i) How will you distinguish primary, secondary and tertiary alcohol by Lucas Test ? (ii) What happens when anisole is nitrated ? **OR**…Preview
- Q20$HO-CH_2-CH_2-OH$ on heating with periodic acid gives : (a) Methanal (b) Methanoic acid (c) $CO_2$ (d) GlyoxalPreview
- Q21Give the IUPAC names : (a) $CH_3-C(CH_3)(OH)-CH_3$ [2-methylpropan-2-ol structure: a central carbon bonded to three $CH_3$ groups and one $O…Preview
- Q22Write any one method of preparation for diethyl ether.Preview
- Q23Which of the following compound is used as an anti-freeze in automobile radiator ? (a) Methanol (b) Ethane-1, 2-diol (c) Ethanol (d) Glycero…Preview
- Q24The oxidising agent used to stop the oxidation of primary alcohol at the aldehyde stage is : (a) $Na_2Cr_2O_7$ (b) $KMnO_4$ (c) $K_2Cr_2O_7$…Preview
- Q25Write Kolbe's reaction.Preview
- Q26Which one of the following is the Strongest acid ? (a) 4-nitrophenol (b) 2-nitrophenol (c) 3-nitrophenol (d) 4-chlorophenolPreview
- Q27Find the products X and Y in the following reactions. Phenol (OH on benzene ring) $\xrightarrow[\Delta]{Zn}$ X Phenol (OH on benzene ring) $…Preview
- Q28Propan-2-ol on reaction with anhydrous $ZnCl_2$ and concentrated HCl gives ________. (a) 1-chloropropane (b) Ethyl chloride (c) 2-chloro-2-m…Preview
- Q29How will you convert phenol to phenolphthalein ?Preview