Chapter 27

Ethyl ester \(\stackrel{\mathrm{CH}_{3} \mathrm{MgBr} \text { (excess) }}{\longrightarrow} \mathrm{P}\) The product ' \(\mathrm{P}\) ' will be

Identify the product ' \(\mathrm{P}\) ' in the given reaction \(\mathrm{C}_{6} \mathrm{H}_{5} \mathrm{OH}+\mathrm{C}_{2} \mathrm{H}_{5} \mathrm{I} \quad \frac{\mathrm{O}^{-} \mathrm{C}_{2} \mathrm{H}_{3}}{\text { Anhy. }\left(\mathrm{C}_{2} \mathrm{H}_{3} \mathrm{OH}\right)}\) (a) \(\mathrm{C}_{6} \mathrm{H}_{5} \mathrm{OC}_{2} \mathrm{H}_{5}\) (b) \(\mathrm{C}_{2} \mathrm{H}_{3} \mathrm{OC}_{2} \mathrm{H}_{5}\) (c) \(\mathrm{C}_{6} \mathrm{H}_{5} \mathrm{OC}_{6} \mathrm{H}_{5}\) (d) \(\mathrm{C}_{6} \mathrm{H}_{5} \mathrm{I}\).

1-propanol and 2 -propanol can be best distinguished by (a) oxidation with \(\mathrm{KMnO}_{4}\) followed by reaction with Fehling solution (b) oxidation with acidic dichromate followed by reaction with Fehling solution (c) oxidation by heating with copper followed by reaction with Fehling solution (d) oxidation with concentrated \(\mathrm{H}_{2} \mathrm{SO}_{4}\) followed by reaction

An organic compound \(\mathrm{C}_{3} \mathrm{H}_{6} \mathrm{O}\) does not give a precipitate with 2,4 -dinitrophenylhydrazine and does not react with metallic sodium. It could be (a) \(\mathrm{CH}_{3}-\mathrm{CH}_{2}-\mathrm{CHO}\) (b) \(\mathrm{CH}_{2}=\mathrm{CH}-\mathrm{CH}_{2} \mathrm{OH}\) (c) \(\mathrm{CH}_{3}-\mathrm{CO}-\mathrm{CH}_{3}\) (d) \(\mathrm{CH}_{2}=\mathrm{CH}-\mathrm{O}-\mathrm{CH}_{3}\)

The compound which gives the most stable carbonium ion on dehydration is (a) \(\left(\mathrm{CH}_{3}\right)_{2} \mathrm{CHCH}_{2} \mathrm{OH}\) (b) \(\left(\mathrm{CH}_{3}\right)_{3} \mathrm{COH}\) (c) \(\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{OH}\) (d) \(\mathrm{CH}_{3} \mathrm{CHOHCH}_{2} \mathrm{CH}_{3}\)

Which of the following reactions will yield propan-2-ol? \(1 \mathrm{CH}_{2}=\mathrm{CH}-\mathrm{CH}_{3}+\mathrm{H}_{2} \mathrm{O}\) \(\stackrel{\mathrm{H}^{\prime}}{\longrightarrow}\) \(2 \mathrm{CH}_{3}-\mathrm{CHO}-\frac{\text { (i) } \mathrm{CH}_{\mathrm{s}} \mathrm{Mgl}}{\text { (ii) } \mathrm{H}_{2} \mathrm{O}}\) \(3 \mathrm{CH}_{2} \mathrm{O} \frac{\text { (i) } \mathrm{C}_{2} \mathrm{H}_{3} \mathrm{Mgl}}{\text { (ii) } \mathrm{H}_{2} \mathrm{O}}\) \(4 \mathrm{CH}_{2}=\mathrm{CH}-\mathrm{CH}_{3} \stackrel{\text { Neutral } \mathrm{KMnO}_{4}}{\longrightarrow}\) (a) 1 and 2 (b) 2 and 3 (c) 3 and 1 (d) 2 and 4

Identify the correct order of boiling points of the following compounds: \(\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{OH}\) (I) \(\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{CHO}\) (II) \(\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{COOH}\) (III) (a) \(\mathrm{I}>\mathrm{II}>\mathrm{III}\) (b) III > I > II (c) \(\mathrm{I}>\mathrm{III}>\mathrm{II}\) (d) \(\mathrm{III}>\mathrm{II}>\mathrm{I}\)

Consider the following species: 1\. \(\mathrm{RCHCH}_{3}\) 2\. \(\mathrm{RCH}_{2} \mathrm{CH}_{2}^{+} \quad\) 3. \(\mathrm{RCH}_{2} \mathrm{CH}_{2} \mathrm{OH}_{2}^{+}\) In the dehydration of primary alcohols, the correct sequence of formation of the species involved is (a) \(1,2,3\) (b) \(1,3,2\) (c) \(3,2,1\) (d) \(2,1,3\)

Consider the following alcohols 1\. 1-phenyl-1-propanol 2\. 3-phenyl-1-propanol 3\. 1-phenyl-2-propanol The correct sequence of the increasing order of reactivity of these alcohols in their reaction with \(\mathrm{HBr}\) is (a) \(1,3,2\) (b) \(2,3,1\) (c) \(2,1,3\) (d) \(1,2,3\)

In the reaction, \(\mathrm{H}_{3} \mathrm{C}-\mathrm{C} \equiv \mathrm{CH} \longrightarrow \mathrm{H}_{3} \mathrm{C}-\mathrm{CH}(\mathrm{OH})-\mathrm{CH}_{3}\), the reagent used would include (a) \(\mathrm{Hg}^{2+} / \mathrm{H}_{2} \mathrm{SO}_{4}\) (b) Na in liquid \(\mathrm{NH}_{3}\), followed by \(\mathrm{CH}_{3} \mathrm{Cl}\) (c) \(1 \mathrm{~mol}\) of \(\mathrm{H}_{2} / \mathrm{Pt}\), followed by \(\mathrm{H}_{2} \mathrm{SO}_{4} / \mathrm{H}_{2} \mathrm{O}\) (d) \(2 \mathrm{~mol}\) of \(\mathrm{H}_{2} / \mathrm{Pt}\), followed by aq. \(\mathrm{NaOH}\)

Match the following: List I 1\. absolute alcohol 2\. denatured alcohol 3\. \(80 \%\) proof alcoholic liquor 4\. rubbing alcohol List II (i) alcohol made undrinkable by the addition of toxic materials or poisons. (ii) alcoholic liquor containing \(40 \%\) ethanol by volume (iii) anhydrous alcohol (iv) isopropyl alcohol The correct matching is:

Under different conditions, nitration of phenol yields 1\. o-nitrophenol 2\. p-nitrophenol 3\. \(2,4,6\)-trinitrophenol The correct sequence of decreasing order of acidic nature of these phenols is (a) \(3,2,1\) (b) \(1,2,3\) (c) \(2,1,3\) (d) \(3,1,2\)

Which of the following reactions will yield 2-propanol? (1) \(\mathrm{CH}_{2}=\mathrm{CH}-\mathrm{CH}_{3}+\mathrm{H}_{2} \mathrm{O} \stackrel{\mathrm{H}^{\prime}}{\longrightarrow}\) (2) \(\mathrm{CH}_{3} \mathrm{CHO} \stackrel{\text { (i) } \mathrm{CH}_{3} \mathrm{MgI}, \text { (ii) } \mathrm{H}_{2} \mathrm{O}}{\longrightarrow}\) (3) \(\mathrm{CH}_{2} \mathrm{O} \quad\) (i) \(\mathrm{C}_{2} \mathrm{H}_{3} \mathrm{Mgl}\), (ii) \(\mathrm{H}_{2} \mathrm{O}\) (4) \(\mathrm{CH}_{2}=\mathrm{CH}-\mathrm{CH}_{3} \stackrel{\text { Neutral } \mathrm{KMnO}_{4}}{\longrightarrow}\) (a) 1 and 3 (b) 2 and 4 (c) 1 and 2 (d) 3 and 4

Identify the correct statements. (a) \(\mathrm{C}_{2} \mathrm{H}_{5}-\mathrm{O}-\mathrm{CH}_{3}\) on cleavage with \(\mathrm{PCl}_{5}\) gives equimolar mixture of ethyl chloride and methyl chloride (b) \(\mathrm{ClCH}_{2} \mathrm{CH}=\mathrm{CH}_{2}\) is more reactive than \(\mathrm{BrCH}_{2} \mathrm{CH}_{2} \mathrm{CH}_{3}\) to prepare ether using Williamson's synthesis (c) Anisole can be prepared by the reaction of 1 \(\mathrm{CH}_{3} \mathrm{ONa}\) on chlorobenzene (d) Sodium metal can be used to dry diethyl ether, benzene and ethyl alcohol.

Select wrong statements: (a) Phenols turn blue litmus to red. (b) Reactivity of methanol with sodium metal is more than that of isopropyl alcohol (c) Methanol gives iodoform test. (d) Phenol reacts with \(\mathrm{Na}_{2} \mathrm{CO}_{3}\) and liberates \(\mathrm{CO}_{2}\) gas

Which of the following ethers cannot be synthesized by directly williamson's ether synthesis?

Luca's test of alcohols involves following reaction: \(\mathrm{R}-\mathrm{OH}+\mathrm{HCl} \frac{\text { anhydrous }}{\mathrm{ZnCl}_{2}} \underset{\text { white turbidity }}{\mathrm{RCl}+\mathrm{H}_{2} \mathrm{O}}\) Select the correct statement(s) for the Luca's test. (a) Lesser the acidic character of alcohol, greater is its reactivity towards Luca's reagent. (b) ROH behaves as a base. (c) \(\mathrm{CH}_{3} \mathrm{OH}\) gives Luca's test most quickly. (d) Reactivity of \(1^{\circ}, 2^{\circ}, 3^{\circ}\) alcohol, lies in the following sequence (for Luca's reaction \(3^{\circ}>2^{\circ}>1^{\circ}\) ).

Which of the following is/are correct? (a) Phenol gives paraquinol with \(\mathrm{S}_{2} \mathrm{O}_{8}^{-2} / \mathrm{OH}^{-}\)as a major product. (b) Phenol can give electrophilic aromatic substitution reactions in absence of lewis acid. (c) Salicylic acid can give white/yellow solution with \(\mathrm{Br}_{2} / \mathrm{CS}_{2}\) (d) Ipso substitution is possible in phenol derivative if it contains \(-\mathrm{COOH}\) or \(-\mathrm{SO}_{3} \mathrm{H}\) group at ortho or para position with respect to OH group.

Carbonyl compounds on reduction with selective reducing agents give alcohols. The structure of alcohol formed depends upon the nature of reducing agents. \(\operatorname{LiAlH}_{4}\), \(\mathrm{NaBH}_{,}\), sodium alcohol, \(\mathrm{Mg}(\mathrm{Hg}) \mathrm{H}, \mathrm{O}\) etc can be used. When \(\mathrm{CH}_{3}-\mathrm{CH}=\mathrm{CH}-\mathrm{CHO}\) is reduced with \(\mathrm{NaBH}_{4}\), the product formed is (a) \(\mathrm{CH}_{3}-\mathrm{CH}=\mathrm{CH}-\mathrm{CH}_{2} \mathrm{OH}\) (b) \(\mathrm{CH}_{3}-\mathrm{CH}_{2}-\mathrm{CH}_{2}-\mathrm{CHO}\) (c) \(\mathrm{CH}_{3}-\mathrm{CH}_{2}^{2}-\mathrm{CH}_{2}^{2}-\mathrm{CH}_{3}\) (d) \(\mathrm{CH}_{3}^{3}-\mathrm{CH}_{2}-\mathrm{CH}_{2}-\mathrm{CH}_{2} \mathrm{OH}\)

Phenols undergo aromatic electrohiilic substitution, since OH groups is a strong activating substituent. A phenolic derivative \(X\) upon nitration gives two isomeric mononitro derivatives. Possible structure of \(\mathrm{X}\) is

How many moles of methyl magnesium iodide in ether will react with a molecule of ethylchloroformate to form a \(3^{\circ}\) alcohol?

A compound with molecular formula \(\mathrm{C}_{6} \mathrm{H}_{14} \mathrm{O}_{5}\) is converted by the action of acetyl chloride to a compound with molecular mass 334 . The number of OH groups in the compound is

Out of the following the number of compounds which can be used to remove water from alcohol is \(\mathrm{CaO}, \mathrm{Na}, \mathrm{Mg}, \mathrm{CaCl}_{2},\left(\mathrm{C}_{2} \mathrm{H}_{5} \mathrm{O}\right)_{2} \mathrm{Mg}\), conc. \(\mathrm{H}_{2} \mathrm{SO}_{4}, \mathrm{PCl}_{5}\)

\(5.2 \mathrm{~g}\) of polyhydric alcohol was treated with an excess of methyl magnesium bromide to produce \(3.36\) litre of \(\mathrm{CH}_{4}\) at STP. Calculate number of \(\mathrm{OH}\) groups present in polyhydric alcohol (molar mass of alcohol \(=104 \mathrm{~g}\) \(\left.\mathrm{mol}^{-1}\right)\)

An ether is more volatile than an alcohol having the same molecular formula. This is due to (a) dipolar character of ethers (b) alcohols having resonance structures (c) intermolecular hydrogen bonding in ethers (d) inter molecular hydrogen bonding in alcohols

During dehydration of alcohols to alkenes, by heating with concentrated \(\mathrm{H}_{2} \mathrm{SO}_{4}\) the initiation step is (a) formation of an ester (b) elimination of water (c) protonation of alcohol molecule (d) formation of a carbocation

Which one of the following undergoes reaction with \(50 \%\) sodium hydroxide solution to give the corresponding alcohol and acid? (a) phenol (b) benzaldehyde (c) butanal (d) benzoic acid

The IUPAC name of (a) 3, 3-dimethyl-1-hydroxycyclohexane (b) 1,1 -dimethyl-3-hydroxycyclohexane (c) 3,3 -dimethyl-1-cyclohexanol (d) 1, 1 -dimethyl-3-cyclohexanol

The best reagent to convert pent-3-en-2-ol into pent3-en-2-one is (a) acidic permanganate (b) acidic dichromate (c) chromic anhydride in glacial acetic acid (d) pyridinium chlorochromate

Acid catalysed hydration of alkenes, except ethene, leads to the formation of (a) primary alcohol (b) secondary or tertiary alcohol (c) mixture of primary and secondary alcohols (d) mixture of secondary and tertiary alcohols

Phenol, when it first reacts with concentrated sulphuric acid and then with concentrated nitric acid, gives (a) \(2,4,6\)-trinitrobenzene (b) o-nitrophenol (c) p-nitrophenol (d) Nitrobenzene

Bakelite is obtained from phenol by reacting with (a) \(\left(\mathrm{CH}_{2} \mathrm{OH}\right)_{2}\) (b) \(\mathrm{CH}_{3} \mathrm{CHO}\) (c) \(\mathrm{CH}_{4} \mathrm{COCH}_{3}\) (d) \(\mathrm{HCHO}\)

The major product obtained on interaction of phenol with sodium hydroxide and carbon dioxide is: (a) salicylaldehyde (b) salicylic acid (c) phthalic acid (d) benzoic acid

From amongst the following alcohols the one that would react fastest with conc. HCl and anhydrous \(\mathrm{ZnCl}_{2}\), is (a) 2-Butanol (b) 2 -Methylpropan \(-2\)-ol (c) 2-Methylpropanol (d) 1 -Butanol

Which of the following reagents may be used to distinguish between phenol and benzoic acid? (a) Tollen's reagent (b) Molisch reagent (c) Neutral \(\mathrm{FeCl}_{3}\) (d) Aqueous \(\mathrm{NaOH}\)

Phenol is heated with a solution of mixture of \(\mathrm{KBr}\) and \(\mathrm{KBrO}_{3} .\) The major product obtained in the above reaction is (a) 3-Bromophenol (b) 4-Bromophenol (c) \(2,4,6\)-Tribromophenol (d) 2-Bromophenol

Iodoform can be prepared from all except (a) 3 - methyl \(-2\)-butanone (b) Isopropyl alcohol (c) Ethyl methyl ketone (d) Isobutyl alcohol

Ortho \(-\) Nitrophenol is less soluble in water than pand \(\mathrm{m}-\) Nitrophenols because (a) Melting point of o- Nitrophenol is lower than those of \(\mathrm{m}\) - and \(\mathrm{p}\) - isomers (b) o- Nitrophenol is more volatile in steam than those of \(\mathrm{m}\) - and \(\mathrm{p}\) - isomers (c) o- Nitrophenol shows Intramolecular H-bonding (d) o- Nitrophenol shows Intermolecular H-bonding

An unknown alcohol is treated with the "Lucas reagent" to determine whether the alcohol is primary, secondary or tertiary. Which alcohol reacts fastest and by what mechanism (a) secondary alcohol by \(\mathrm{S}_{\mathrm{N}^{2}}\) (b) tertiary alcohol by \(\mathrm{S}_{\mathrm{N}^{2}}\) (c) Secondary alcohol by \(\mathrm{S}_{\mathrm{N} 1}\) (d) tertiary alcohol by \(\mathrm{S}_{\mathrm{N}^{1}}\)