Chemistry Organic Chemistry questions from JEE Main 2020.
$1$-methyl ethylene oxide when treated with an excess of $HBr$ produces
A chromatography column, packed with silica gel as stationary phase, was used to separate a mixture of compounds consisting of $(A)$ benzanilide $(B)$ aniline and $(C)$ acetophenone. When the column is eluted with a mixture of solvents, hexane:ethyl acetate $(20:80)$ , the sequence of obtained compounds is:
A flask contains a mixture of isohexane and $3$ -methylpentane. One of the liquids boils at ${63}^{o}C$ while the other boils at ${60}^{o}C.$ What is the best way to separate the two liquids and which one will be distilled out first?
A solution of $m-$ chloroaniline, $m-$ chlorophenol and $m-$ chlorobenzoic acid in ethyl acetate was extracted initially with a saturated solution of $NaHC{O}_{3}$ to give fraction $A$ . The left over organic phase was extracted with dilute $NaOH$ solution to give fraction $B$ . The final organic layer was labelled as fraction $C$ . Fractions $A,B$ and $C,$ contain respectively:
A solution of phenol in chloroform when treated with aqueous $\mathrm{NaOH}$ gives compound $P$as a major product. The mass percentage of carbon in $P$ is ______ .
Among the following compounds, geometrical isomerism is exhibited by :
Among the following compounds, which one has the shortest $C–\mathrm{Cl}$ bond?
An organic compound (A) (molecular formula ${C}_{6}{H}_{12}{O}_{2}$) was hydrolysed with dil. ${H}_{2}{\mathrm{SO}}_{4}$ to give a carboxylic acid (B) and an alcohol (C). ‘$C$ ’ gives white turbidity immediately when treated with anhydrous ${\mathrm{ZnCl}}_{2}$ and conc. $\mathrm{HCl}$. The organic compound (A) is:
An organic compound [A], molecular formula ${C}_{10}{H}_{20}{O}_{2}$ was hydrolyzed with dilute sulphuric acid to given a carboxylic acid [B] and an alcohol [C]. Oxidation of [C] with ${\mathrm{CrO}}_{3}-{H}_{2}{\mathrm{SO}}_{4}$ produced [B]. Which of the following structures are not possible for $[A]$
An organic compound '$A$' $({C}_{9}{H}_{10}O)$ when treated with conc. $\mathrm{HI}$ undergoes cleavage to yield compound '$B$' and '$C$'. '$B$' gives yellow precipitate with ${\text{AgNO}}_{3}$ where as '$C$' tautomerizes to '$D$'. '$D$' gives positive iodoform test. '$A$' could be:
An unsaturated hydrocarbon $X$ absorbs two hydrogen molecules on catalytic hydrogenation, and also gives following reaction: $X\overset{(i){O}_{3}}{\underset{\frac{(\mathrm{ii})\mathrm{Zn}}{{H}_{2}O}}{\rightarrow }}A\overset{{[\mathrm{Ag}{({\mathrm{NH}}_{3})}_{2}]}^{+}}{\rightarrow }B$ (3-oxo-hexanedicarboxylic acid) $X$ will be:
$A,B$ and $C$ are three biomolecules. The results of the tests performed on them are given below:<table class="pyq-table"><tbody><tr><th></th><th>Molisch's test</th><th>Barfoed Test</th><th>Biuret Test</th></tr><tr><td>$A$</td><td>Positive</td><td>Negative</td><td>Negative</td></tr><tr><td>$B$</td><td>Positive</td><td>Positive</td><td>Negative</td></tr><tr><td>$C$</td><td>Negative</td><td>Negative</td><td>Positive</td></tr></tbody></table> $A,B$ and $C$ are respectively:
Arrange the following compounds in increasing order of $C-OH$ bond length: methanol, phenol, $p$ -ethoxyphenol
Arrange the following labelled hydrogens in decreasing order of acidity: 
Consider the following plots of rate constant versus $\frac{1}{T}$ for four different reactions. Which of the following orders is correct for the activation energies of these reactions? 
Consider the following reaction:  The product $'{X}^{'}$ is used:
Consider the following reaction:  The product$'P'$gives positive ceric ammonium nitrate test. This is because of the presence of which of these$–\mathrm{OH}$ group(s)?
Consider the following reactions : (i) Glucose $+\mathrm{ROH}\overset{\mathrm{dry} \mathrm{HCI}}{\rightarrow }\mathrm{Acetal} \rightarrow _{{({\mathrm{CH}}_{3}\mathrm{CO})}_{2}}^{x \mathrm{eq}. \mathrm{of}}$ acetyl derivative (ii) Glucose $\overset{\mathrm{Ni}/{H}_{2}}{\rightarrow }A\rightarrow _{{({\mathrm{CH}}_{3}\mathrm{CO})}_{2}O}^{y \mathrm{eq}. \mathrm{of}}$ acetyl derivative (iii) Glucose $\rightarrow _{{({\mathrm{CH}}_{3}\mathrm{CO})}_{2}O}^{z \mathrm{eq}. \mathrm{of}}$ acetyl derivative '$x$' , '$y$' and '$z$' in these reactions are respectively.
Consider the following reactions:  'A' is
Consider the following reactions: $(a)$ ${(C{H}_{3})}_{3}CCH(OH)C{H}_{3}\overset{conc.{H}_{2}S{O}_{4}}{\rightarrow }$ $(b)$ ${(C{H}_{3})}_{2}CHCH(Br)C{H}_{3}\overset{alc.KOH}{\rightarrow }$ $(c)$ ${(C{H}_{3})}_{2}CHCH(Br)C{H}_{3}\overset{{(C{H}_{3})}_{3}{O}^{\ominus }{K}^{\oplus }}{\rightarrow }$ $(d)$  Which of the reaction(s) will not produce Saytzeff product?
Consider the following reactions:     Which of these reactions are possible?
Consider the following reactions,  The compound $[P]$ is:
Consider the following reactions $A\frac{(i)C{H}_{3}MBr}{(ii){H}_{3}{O}^{+}}B\frac{Cu}{573K}2-methyl-2-butene$ . The mass percentage of carbon in $A$ is _____________.
Consider the reaction sequence given below :  Which of the following statements is true:
Which functional group is present in an ester?
The product obtained when ethanol reacts with concentrated H₂SO₄ at 170°C is:
For the following Assertion and Reason, the correct option is: Assertion: For hydrogenation reactions, the catalytic activity increases from Group $5$ to Group $11$ metals with maximum activity shown by Group $7-9$ elements. Reason: The reactants are most strongly adsorbed on group $7-9$ elements.
For the following reactions  where,  ${k}_{s}$ and ${k}_{e}$ , are respectively, the rate constants for substitution and elimination, and $\mu =\frac{{k}_{s}}{{k}_{e}}$ , the correct option is ________
Glycerol is separated in soap industries by :
Identify $(A)$ in the following reaction sequence: 
In an estimation of bromine by Carius method, $1.6g$ of an organic compound gave $1.88g$ of $\mathrm{AgBr}$. The mass percentage of bromine in the compound is $\ldots ..$ $($Atomic mass, $\mathrm{Ag}=108,\mathrm{Br}=80{\mathrm{gmol}}^{-1}$
In Carius method of estimation of halogen, $0.172g$ of an organic compound showed presence of $0.08g$ of bromine. Which of these is the correct structure of the compound ?
In the following reaction $A$ is 
In the following reaction sequence, $[C]$ is : 
In the following reaction sequence,  the major product $B$ is
In the following reaction sequence, structures of $A$ and $B$ are, respectively 
In the following reaction sequence the major products $A$ and $B$ are : 
In the following sequence of reactions the maximum number of atoms present in molecule ‘ $C$ ’ in one plane is_______ $A\overset{Red hot}{\underset{Cu tube}{\rightarrow }}B\overset{C{H}_{3}Cl(1.eq)}{\underset{Anhydrous AlC{l}_{3}}{\rightarrow }}C$ (A is a lowest molecular weight alkyne)
Kjeldahl’s method cannot be used to estimate nitrogen for which of the following compounds?
Match the following :<table class="pyq-table"><tbody><tr><th>$(i)$</th><th>Riboflavin</th><th>$(a)$</th><th>Beriberi</th></tr><tr><td>$(ii)$</td><td>Thiamine</td><td>$(b)$</td><td>Scurvy</td></tr><tr><td>$(iii)$</td><td>Pyridoxine</td><td>$(c)$</td><td>Cheilosis</td></tr><tr><td>$(iv)$</td><td>Ascorbic acid</td><td>$(d)$</td><td>Convulsions</td></tr></tbody></table>
Match the following : <table class="pyq-table"><tbody><tr><td></td><td>Test/Method</td><td></td><td>Reagent</td></tr><tr><td>(i)</td><td>Lucas Test</td><td>(a)</td><td>${C}_{6}{H}_{5}{\mathrm{SO}}_{2}\mathrm{Cl}/\mathrm{aq}.\mathrm{KOH}$</td></tr><tr><td>(ii)</td><td>Dumas method</td><td>(b)</td><td>${\mathrm{HNO}}_{3}/{\mathrm{AgNO}}_{3}$</td></tr><tr><td>(iii)</td><td>Kjeldahl's method</td><td>(c)</td><td>$\mathrm{CuO}/{\mathrm{CO}}_{3}$</td></tr><tr><td>(iv)</td><td>Hinsberg Test</td><td>(d)</td><td>Conc. $\mathrm{HCl}$ and ${\mathrm{ZnCl}}_{2}$</td></tr><tr><td></td><td></td><td>(e)</td><td>${H}_{2}{\mathrm{SO}}_{4}$</td></tr></tbody></table>
$[P]$ on treatment with ${\mathrm{Br}}_{2}/{\mathrm{FeBr}}_{3}$ in ${\mathrm{CCl}}_{4}$ produced a single isomer ${C}_{8}{H}_{7}{O}_{2}\mathrm{Br}$ wile heating $[P]$ with sodalime gives toluene. The compound $[P]$ is:
The compound A in the following reactions is: $A\rightarrow _{(\mathrm{ii})\mathrm{Conc}.{H}_{2}{\mathrm{SO}}_{4}/\Delta }^{(i){\mathrm{CH}}_{3}\mathrm{MgBr}/{H}_{2}O} B\rightarrow _{(\mathrm{ii})\mathrm{Zn}/{H}_{2}O}^{(i){O}_{3}}C+D$ 
The correct match between Item-I (starting material) and Item-II (reagent) for the preparation of benzaldehyde is : <table class="pyq-table"><tbody><tr><td></td><td>Item-I</td><td></td><td>Item-II</td></tr><tr><td>(I)</td><td>Benzene</td><td>(P)</td><td>$\mathrm{HCl}$ and ${\mathrm{SnCl}}_{2},{H}_{3}O+$</td></tr><tr><td>(II)</td><td>Benzonitrile</td><td>(Q)</td><td>${H}_{2},\mathrm{Pd}-{\mathrm{BaSO}}_{4},S$ and quinoline</td></tr><tr><td>(III)</td><td>Benzoyl Chloride</td><td>(R)</td><td>$\mathrm{Co},\mathrm{HCl}\mathrm{and}{\mathrm{AlCl}}_{3}$</td></tr></tbody></table>
The correct observation in the following reaction is: $\mathrm{Sucrose}\rightarrow _{\mathrm{Cleavage}(\mathrm{Hydrolysis})}^{\mathrm{Gly}\mathrm{cosidic}\mathrm{bond}}A+B\rightarrow _{\mathrm{Reagent}}^{\mathrm{Seliw}\mathrm{anoff}}?$
The correct order of heat of combustion for following alkadienes is: 
The correct order of stability for the following alkoxides is: 
The correct order of the calculated spin-only magnetic moments of complexes $(A)$ to $(D)$ is: $(A)$ $Ni{(CO)}_{4}$ $(B)$ $[Ni{({H}_{2}O)}_{6}]C{l}_{2}$ $(C)$ $N{a}_{2}[Ni{(CN)}_{4}]$ $(D)$ $PdC{l}_{2}{(PP{h}_{3})}_{2}$
The decreasing order of basicity of the following amines is: 
The decreasing order of reactivity of the following compounds towards nucleophilic substitution (${S}_{N}2$) is: 
The decreasing order of reactivity of the following organic molecules towards ${\mathrm{AgNO}}_{3}$ solution is: 
The decreasing order of reactivity towards dehydrohalogenation $({E}_{1})$ reaction of the following compounds is: 
The final major product of the following reaction is : 
The increasing order of basicity for the following intermediates is (from weak to strong) 
The increasing order of basicity of the following compounds is : 
The increasing order of $p{K}_{b}$ for the following compounds will be : 
The increasing order of the acidity of the $\alpha$-hydrogen of the following compounds is:  $(A)(B)(C)(D)$
The increasing order of the boiling points of the major products $A,B$ and $C$ of the following reactions will be : (a)  (b)  (c) 
The increasing order of the following compounds towards $\mathrm{HCN}$ addition is : (i)  (ii)  (iii)(iv) 
The increasing order of the reactivity of the following compounds in nucleophile addition reaction is: Propanal, Benzaldehyde, Propanone, Butanone
The increasing order of ${\mathrm{pK}}_{b}$ values of the following compounds is : 
The IUPAC name of following compound is : 
The IUPAC name of the following compound is: 
The Kjeldahl method of Nitrogen estimation fails for which of the following reaction products? 
The major aromatic product $C$ in the following reaction sequence will be : 
The major product formed in the following reaction is : ${\mathrm{CH}}_{2}\mathrm{CH}=\mathrm{CHCH}{({\mathrm{CH}}_{3})}_{2}\overset{\mathrm{HBr}}{\rightarrow }$
The major product $[B]$ in the following reaction is : 
The major product in the following reaction is : 
The major product in the following reaction is: 
The major product $(Y)$ in the following reactions is: 
The major product $[R]$ in the following sequence of reaction is : 
The major product obtained from ${E}_{2}$-elimination of $3-\mathrm{bromo}-2-\mathrm{fluoropentane}$ is
The major product obtained from the following reaction is : 
The major product $Z$ obtained in the following reaction scheme is: 
The major product of the following reaction is : 
The major product of the following reaction is : 
The major product of the following reaction is: 
The major product of the following reaction is: 
The major product $[C]$ of the following reaction sequence will be : 
The major products $A$ and $B$ in the following reactions are 
The major products of the following reaction are : 
The mechanism of Sn1 reaction is given as: $R-X\longrightarrow {R}^{\oplus }{X}^{\ominus }\longrightarrow {R}^{\oplus }\|{X}^{\ominus }\overset{{Y}^{\ominus }}{\longrightarrow }R-Y+{X}^{\ominus } \mathrm{lon}\mathrm{pair}\mathrm{Solvent} \mathrm{Speparated}\mathrm{ion} \mathrm{pair}$ A student writes general characteristics based on the given mechanism as : (a) The reaction is favoured by weak nucleophiles. (b) ${R}^{\oplus }$ would be easily formed if the substituents are bulky $y$ (c) The reaction is accompanied by recemization (d) The reaction is favoured by non-polar solvents. Which observations are correct?
The minimum number of moles of ${O}_{2}$ required for complete combustion of 1 mole of propane and 2 moles of butane is..............
The most appropriate reagent for conversion of ${C}_{2}{H}_{5}\mathrm{CN}$ into ${\mathrm{CH}}_{3}{\mathrm{CH}}_{2}{\mathrm{CH}}_{2}{\mathrm{NH}}_{2}$ is :
The most suitable reagent for the given conversion is:  
The $\mathrm{IUPAC}$ name for the following compound is : 
The number of chiral carbon(s) present in peptide, lle-Arg-Pro, is ................
The number of chiral carbons present in sucrose is ……….
The number of chiral carbons present in the molecule given below is.............. 
The number of chiral centres present in $[B]$ is _____ 
The number of chiral centres present in threonine is _________
The number of $s{p}^{2}$ hybrid orbitals in a molecule of benzene is:
The number of  groups present in a tripeptide Asp – Glu – Lys is ____
The total number of monohalogenated organic products in the following (including stereoisomers) reaction is $\underset{(\mathrm{Simplest}\mathrm{optically} \mathrm{active}\mathrm{alkene})}{A}\rightarrow _{(\mathrm{ii}){X}_{2}/\Delta }^{(i){H}_{2}/\mathrm{Ni}/\Delta }$
Three isomers A, B and C (mol. formula ${C}_{8}{H}_{11}N$ ) give the following results: $A$ and $C$$\overset{\mathrm{Dianotization}}{\rightarrow }P+Q\rightarrow _{(\mathrm{ii})\mathrm{acidation} ({\mathrm{KMnO}}_{4}+{H}^{+})}^{(i)\mathrm{Hydrolyds}}R(\mathrm{product}\mathrm{of}A)+S(\mathrm{product}\mathrm{of}C)$ R has lower boiling point than S $B\overset{{C}_{6}{H}_{5}{\mathrm{SO}}_{2}\mathrm{Cl}}{\rightarrow }$ alkali-insoluble product $A,B$ and $C,$ respectively are:
Two compounds $A$ and $B$ with same molecular formula $({C}_{3}{H}_{6}O)$ undergo Grignard reaction with methylmagnesium bromide to give products $C$ and $D$. Products $C$ and $D$ show following chemical tests. <table class="pyq-table"><tbody><tr><td>Test</td><td>C</td><td>D</td></tr><tr><td>Ceric ammonium nitrate Test</td><td>Positive</td><td>Positive</td></tr><tr><td>Lucas Test</td><td>Turbidity obtained after five minutes</td><td>Turbidity obtained Immediately</td></tr><tr><td>Iodoform Test</td><td>Positive</td><td>Negative</td></tr></tbody></table>$C$ and $D$ respectively are
What are the functional groups present in the structure of maltose?
What is the product of following reaction?  ?
When neopentyl alcohol is heated with an acid, it slowly converted into an 85 : 15 mixture of alkenes A and B, respectively. What are these alkenes?
Which of the following compounds can be prepared in good yield by Gabriel phthalimide synthesis ?
Which of the following compounds produces an optically inactive compound on hydrogenation?
Which of the following compounds shows geometrical isomerism?
Which of the following compounds will form the precipitate with $\mathrm{aq}.{\mathrm{AgNO}}_{3}$ solution most readily?
Which of the following compounds will show retention in configuration on nucleophile substitution by ${\mathrm{OH}}^{-}\mathrm{ion}$ ?
Which of the following derivatives of alcohols is unstable in an aqueous base?
Which of the following has the shortest $C-Cl$ bond?
Which of the following is not an essential amino acid?
Which of the following reactions will not produce a racemic product ?
Which of the following statement is not true for glucose?
Which of the following statements is correct?
Which of the following will react with ${\mathrm{CHCl}}_{3}+\mathrm{alc}.\mathrm{KOH}$?
Which of these will produce the highest yield Friedel Crafts reaction?
Which one of the following compounds possesses the most acidic hydrogen?
Which one of the following statement is not true?