General Organic Chemistry – JEE Main Previous Year Questions with Solutions

JEE Main Previous Year Papers Questions of Chemistry With Solutions are available at eSaral.

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Previous Years AIEEE/JEE Mains Questions

Q. Arrange the carbanions, $\left(\mathrm{CH}_{3}\right)_{3} \overline{\mathrm{C}}, \overline{\mathrm{C}} \mathrm{Cl}_{3},\left(\mathrm{CH}_{3}\right)_{2} \overline{\mathrm{C}} \mathrm{H}, \mathrm{C}_{6} \mathrm{H}_{5} \overline{\mathrm{C}} \mathrm{H}_{2}$ , in order of their

decreasing stability

[AIEEE-2009]

Sol. (1)

Q. The non aromatic compound among the following is :-

[AIEEE-2011]

Sol. (1)

Q. ortho-Nitrophenol is less soluble in water than p– and m– Nitrophenols because :-

(1) Melting point of o–Nitrophenol is lower than those of m– and p– isomers

(2) o–Nitrophenol is more volatile in steam than those of m– and p– isomers

(3) o–Nitrophenol shows Intramolecular H–bonding

(4) o–Nitrophenol shows Intermolecular H–bonding

[AIEEE-2012]

Sol. (3)

Q. Which of the following compounds are antiaromatic :-

(1) (1) and (6) (2) (2) and (5) (3) (1) and (5) (4) (5) and (6)

[AIEEE-2012(Online)]

Sol. (4)

Q. Among the following the molecule with the lowest dipole moment is :-

(1) $\mathrm{CHCl}_{3}$

(2) $\mathrm{CH}_{2} \mathrm{Cl}_{2}$

(3) $\mathrm{CCl}_{4}$

(4) $\mathrm{CH}_{3} \mathrm{Cl}$

[AIEEE-2012(Online)]

Sol. (3)

Q. The order of stability of the following carbocations

(1) III > II > I

(2) II > III > I

(3) I > II > III

(4) III > I > II

[JEE-MAIN-2013]

Sol. (4)

Q. For which of the following molecule significant $\mu^{1} 0$

(1) Only (3) (2) (3) and (4) (3) Only (1) (4) (1) and (2)

[JEE-MAIN-2014]

Sol. (2)

So dipole moment per mole (containing $\mathrm{N}_{\mathrm{A}}$ molecules) is non

zero. Some concept applicable for option (4) .

Q. The correct order of increasing basicity of the given conjugate base $\left(\mathrm{R}=\mathrm{CH}_{3}\right.$) is :-

$(1) \mathrm{RCO} \overline{\mathrm{O}}<\mathrm{HC} \equiv \overline{\mathrm{C}}<\overline{\mathrm{N}} \mathrm{H}_{2}<\overline{\mathrm{R}}$

(2) $\mathrm{RCO} \overline{\mathrm{O}}<\mathrm{HC} \equiv \overline{\mathrm{C}}<\overline{\mathrm{R}}<\overline{\mathrm{N}} \mathrm{H}_{2}$

(3) $\quad \overline{\mathrm{R}}<\mathrm{HC} \equiv \overline{\mathrm{C}}<\mathrm{RCO} \overline{\mathrm{O}}<\overline{\mathrm{N}} \mathrm{H}_{2}$

(4) $\mathrm{RCO} \overline{\mathrm{O}}<\overline{\mathrm{N} H}_{2}<\mathrm{HC} \equiv \overline{\mathrm{C}}<\overline{\mathrm{R}}$

[AIEEE-2010]

Sol. (1)

Basic strength $\propto \frac{1}{\text { Stability of conjugate base }}$

Q. The strongest acid amongst the following compounds is ?

(1) $\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CH}(\mathrm{Cl}) \mathrm{CO}_{2} \mathrm{H}$

(2) $\mathrm{ClCH}_{2} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{COOH}$

(3) $\mathrm{CH}_{3} \mathrm{COOH}$

(4) HCOOH

[AIEEE-2011]

Sol. (1)

(Acidity a –I effect)

Q. The correct order of acid strength of the following compounds :-

A. Phenol B. p-Cresol C. m-Nitrophenol D. p- Nitrophenol

(1) C > B > A > D (2) D > C > A > B

(3) B > D > A > C (4) A > B > D > C

[AIEEE-2011]

Sol. (2)

Q. In the following compounds :

the order of basicity is as follows :

(1) IV > III > II > I

(2) II > III > I > IV

(3) I > III > II > IV

(4) III > I > II > IV

[JEE(Main)-2012]

Sol. (3)

Q. The most basic compound among the following is :-

(1) Acetanilide

(2) Benzylamine

(3) p-Nitro aniline

(4) Aniline

[JEE(Main)-2012]

Sol. (2)

Basicity $\propto \frac{1}{\text { Resonance of lone pair e }}$

Q. The order of basicity of amines in gaseous state is :-

(1) $3^{\circ}>2^{\circ}>\mathrm{NH}_{3}>1^{\circ}$

(2) $1^{\circ}>2^{\circ}>3^{\circ}>\mathrm{NH}_{3}$

(3) $\mathrm{NH}_{3}>1^{\circ}>2^{\circ}>3^{\circ}$

(4) $3^{\circ}>2^{\circ}>1^{\circ}>\mathrm{NH}_{3}$

[JEE(Main)-2013]

Sol. (4)

Basicity $\propto+I$ effect

Q. Arrange the following compounds in order of decreasing acidity :

(1) II > IV > I > III

(2) I > II > III > IV

(3) III > I > II > IV

(4) IV > III > I > II

[JEE(Main)-2013]

Sol. (3)

Acidity $\propto-\mathrm{I} /-\mathrm{R} \propto \frac{1}{+\mathrm{I} /+\mathrm{R}}$

Q. The conjugate base of hydrazoic acid is :-

(1) $\mathrm{HN}_{3}^{-}$

(2) $\mathrm{N}_{3}^{-}$

(3) $\mathrm{N}_{2}^{-}$

(4) $\mathrm{N}^{-3}$

[JEE(Main)-2014]

Sol. (2)

$\left(\mathrm{HN}_{3} \longrightarrow \mathrm{N}_{3}+\mathrm{H}^{+}\right)$

Q. Which one of the following compounds will not be soluble in sodium bicarbonate ?

(1) Benzene sulphonic acid

(2) Benzoic acid

(3) o-Nitrophenol

(4) 2, 4, 6 – Trinitrophenol

[JEE(Main)-2014]

Sol. (2)

Due to ortho effect

Q. Considering the basic strength of amines in aqueous solution, which one has

the smallest $\mathrm{pK}_{\mathrm{b}}$ value ?

(1) $\left(\mathrm{CH}_{3}\right)_{3} \mathrm{N}$

(2) $\mathrm{C}_{6} \mathrm{H}_{5} \mathrm{NH}_{2}$

(3) $\left(\mathrm{CH}_{3}\right)_{2} \mathrm{NH}$

(4) $\mathrm{CH}_{3} \mathrm{NH}_{2}$

[JEE(Main)-2014]

Sol. (3)

\begin{aligned} \therefore \text { Due to solvation and inductive effect } \\ 2^{\circ}>1^{\circ}>3^{\circ}>0^{\circ} & \mathrm{R}=-\mathrm{CH}_{3} \end{aligned}

Q. Among the following oxoacids, the correct decreasing order of acid strength is :

(1) $\mathrm{HClO}_{4}>\mathrm{HClO}_{3}>\mathrm{HClO}_{2}>\mathrm{HOCl}$

(2) $\mathrm{HClO}_{2}>\mathrm{HClO}_{4}>\mathrm{HClO}_{3}>\mathrm{HOCl}$

(3) $\mathrm{HOCl}>\mathrm{HClO}_{2}>\mathrm{HClO}_{3}>\mathrm{HClO}_{4}$

(4) $\mathrm{HClO}_{4}>\mathrm{HOCl}>\mathrm{HClO}_{2}>\mathrm{HClO}_{3}$

[JEE(Main)-2014]

Sol. (1)

$\therefore$ Acidic $\propto$ more E.R.S. of conjugate base

Q. The increasing order of basicity of the following compounds is :

(1) (1) < (1) < (3) < (4)

(2) (1) < (1) < (4) < (3)

(3) (4) < (2) < (1) < (3)

(4) (1) < (2) < (3) < (3)

[JEE(Main)-2018]

Sol. (2)

Order of base nature depends on electron donation tendency.

In compoundnitrogen is sp2 hybridized so least basic among all given compound.

compoundis very strong nitrogeneous organic base as lone pair of one nitrogen

delocalize in resonance and make another nitrogen negativly charged and conjugate acid have

two equivalent resonating structure.

Thus it is most basic in given compouds.(secondary amine) more basic than (primary amine)