InterviewSolution
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InterviewSolution
This section includes InterviewSolutions, each offering curated multiple-choice questions to sharpen your knowledge and support exam preparation. Choose a topic below to get started.
| 401. |
Acetic acid is removed from pyroligneous acid by the passing it in-A. `Al(OH)_(3)` solutionB. `Ba(OH)_(2)` solutionC. `Ca(OH)_(2)` solutionD. Ethanol |
| Answer» Correct Answer - C | |
| 402. |
Which of the following is present in pyroligneous acid ?A. Methyl alcoholB. Acetic acidC. AcetoneD. All of these |
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Answer» Correct Answer - D When wood is heated strongly in the absence of air it is gives a brown distillate called pyroligneous acid containing acetic acid `(10%)` , methanol and acetone.Methanol can be separated by fractional distillation over lime. |
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| 403. |
Lucas reagent produces cloudiness immediately withA. `2`-methylpropan`1-ol`B. Butan-`2-ol`C. `2`-methylpropan-`2-ol`D. `CH_(3)CH_(2)Cl` |
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Answer» Correct Answer - D Lucas test is based on the difference in reactivity of three classes of alcohols with `HCl` and distinguishes them from one another. The Lucase reagent, conc.`HCl` and anhydrous `ZnCl_(2)`, converts soluble alcohols to the corresponding alkyl chlorides which are insoluble in the reaction mixture and these appear as a cloudiness or a second more dense layer.A `3^(@)ROH` reacts immediately , a `2^(@)` alcohol reacts within `5`minutes and a `1^(@)ROH` does not react at all at room temperature. `ZnCl_(2)`, a strong Lewis acid , encourages an `S_(N)1` mechanism (i.e. formation of intermediate carbocation ) for formation of th ealkyl chlorides. Thus , the rate of reaction of the alcohols (decided by the stability of carbocations) is : `3^(@) gt 2^(@) gt 1^(@)` `CH_(3)-underset((3^(@)"alcohol")"soluble") underset(2-"Methylpropan-2-ol") underset(OH)underset(|)overset(CH_(3))overset(|)(C)-CH_(3)underset("anhyd".ZnCl_(2))overset("Conc.HCl")rarr CH_(3)-underset("Insoluble")underset(Cl)underset(|)overset(CH_(3))overset(|)(C)-CH_(3)` Remember , Lucas test is useful only for lower alcohols with six or fewer carbon atoms because initially the alcohol must be soluble in the reagent to get protonated. Alcohols having more than six carbon atoms are not soluble , so two layers are present at the start. |
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| 404. |
Alcohols are compounds which have theA. `-OH` groupB. `-OH` group bonded to a saturated carbonC. `-OH` group bonded to a saturated carbonD. `-OH` group bonded to an unsaturated carbon atom |
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Answer» Correct Answer - C Alcohols are compounds whose molecules have a hydroxyl group bonded to a saturated carbon atom of an alkyl group , e.g. `CH_(3)CH_(2) - OH` |
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| 405. |
The compound that will react with HBr most readily is:A. `(CH_(3))_(3)COH`B. `(CH_(3))_(2)CHOH`C. `CH_(3)CH_(2)OH`D. `C_(6)H_(5)OH` |
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Answer» Correct Answer - A Reactivity with HBr is `3^(@)gt2^(@)1^(@)` alcohol, (a) is a `3^(@)` alcohol. Phenol does not react with HBr. `(Ar-O)` bond is not broken unless the ring is activated by the presenced of EWG (e.g., `NO_(2)`) at o-and p-positions. |
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| 406. |
Amongst the following phenols which one is most acidic ?A. Picric acidB. 2-NitrophenoiC. 2,4-DinitrophenolD. m-Nitrophenol |
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Answer» Correct Answer - A Picric acid is the strongest acid due to the presence of thee `(NO_(2)` group (-R and -I effect). |
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| 407. |
Ether reacts with `PCl_(5)` to formA. Ethyl chlorideB. Phosphorous oxy trichlorideC. Both A and BD. None |
| Answer» Correct Answer - C | |
| 408. |
A carbon compound A forms B with sodium metal and again A forms C with `PCl_(5)` but B and C form diethylether. Therefore A, B & C are -A. `C_(2)H_(5)OH,C_(2)H_(5)OH a,C_(2)H_(5)Cl`B. `C_(2)H_(5)Cl,C_(2)H_(5)ON a,C_(2)H_(5)OH`C. `C_(2)H_(5)OH,C_(2)H_(6),C_(2)H_(6)Cl_(2)`D. `C_(2)H_(5)OH,C_(2)H_(5)Cl,C_(2)H_(5)ON a` |
| Answer» Correct Answer - A | |
| 409. |
When ethyl alcohol reacts with acetic acid, the products formed areA. Sodium ethoxide+hydrogenB. Ethyl acetate+waterC. Ethyl acetate+soapD. Ethyl alcohol + water |
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Answer» Correct Answer - B `underset("Acetic acid")(CH_(3)-overset(O)overset(||)(C)-OH+H_(2))O-C_(2)H_(5)overset(H^(+)//Delta)tounderset("Ethylacetate")(CH_(3)-overset(H)overset(||)(C)-OC_(2)H_(5))+underset("water")(H_(2)O)` |
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| 410. |
Complete the following equations & comment (i). `MeOEtoverset(HI)to?` (ii). `Et_(2)Ooverset(Na)to?` |
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Answer» (i) `MeI+EtOH` due to `S_(N)2` mechanism (ii). No reaction. |
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| 411. |
Ethyl iodide reacts with sodium ethoxide to formA. EtheneB. Ethoxy ethaneC. AlcoholD. None |
| Answer» Correct Answer - B | |
| 412. |
Ethyl iodide reacts with most `Ag_(2)O` to formA. EtherB. AlcoholC. AlkeneD. Alkane |
| Answer» Correct Answer - B | |
| 413. |
Ethyl alcohol reacts with HI but not with HCN. Explain why? |
| Answer» Ethanol being very weak Lewis base and thus reacts with stronger acid HI | |
| 414. |
In which of the following reaction alcohol is not formed-A. `R-CH=CH_(2)+H_(2)Ounderset("high pr".)overset(H^(+))to`B. `R-COCl+2H_(2)overset(LiAlH_(4))to`C. `(R-CO)_(2)O+4H_(2)+4H_(2)overset(LiAlH_(4))to`D. `R-CH_(2)-CH_(3)+H_(2)Ounderset("High pr")overset(H^(+))to` |
| Answer» Correct Answer - D | |
| 415. |
Reaction of alcohol does not show cleavage of R-O linkage-A. `ROH+PCl_(5)`B. `ROH+SOCl_(2)`C. `ROH+HCl`D. `ROH+Na` |
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Answer» Correct Answer - D `R-O-H+NatoR-overset(ө)(O)overset(o+)(Na)+1//2H_(2)(uarr)` |
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| 416. |
The most suitable method of separation of a 1:1 mixture of o- and p- nitrophenol is-A. SublimationB. ChromatographyC. crystallisationD. Distillation |
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Answer» Correct Answer - D Due to intramolecular hydrogen bond (chelation) boiling point of o-nitrophenol is less than p-nitrophenol. So they can be separated by distillation. |
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| 417. |
The correct order of reactivity towards electrophilic substitution is-A. PhenolgtBenzenegtChlorobenzenegtBenzoic acidB. Benzoic acidgt ChlorobenzenegtBenzenegtPhenolC. PhenolgtChlorobenzenegtBenzenegt Benzoic acidD. Benzoic acidgtPhenolgtBenzenegtChlorobenzene |
| Answer» Correct Answer - A | |
| 418. |
Which among the following is the strongest ortho-para directing group?A. `-OH`B. `-Cl`C. `-OCH_(3)`D. `-CH_(3)` |
| Answer» Correct Answer - A | |
| 419. |
Which of the following on reaction with aluminimum produces a compound that is used in Meerwein -Ponndrof-Verly reduction of carbonyl compounds?A. `CH_(3)CHOHCH_(3)`B. `CH_(3)CH_(2)OH`C. `CH_(3)OH`D. `(CH_(3))_(3)COH` |
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Answer» Correct Answer - A `MPV` reduction is carried out with aluminium isopropoxide in isopropyl alcohol. Thus to make the alkoxide we need to run the following reaction : `6CH_3-underset("Isopropyl")underset(H)underset(|)overset(CH_3)overset(|)C-OH+2Alrarr2underset("Aluminium isopropoxide")((CH_3-underset(H)underset(|)overset(CH_3)overset(|)C-O)_3)Al+3H_2` |
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| 420. |
Which of the following compounds produces a violet colour on addition of a few drops of `FeCl_(3)` solution?A. Salicylic acidB. Benzoic acidC. tartaric acidD. Citric acid |
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Answer» Correct Answer - A Salicylic acid is `o-`hydroxybenzoic acid. It behaves as a phenol and as an acid. Thus its aqueous solition gives a violet colour with ferric chloride. Note That `m-`hydroxylbenzoic acid does not give a cooration with ferric chloride. |
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