General Organic Chemistry & Isomerism · JEE Main previous year questions

The major organic compound formed by the reaction of 1, 1, 1– trichloroethane with silver powder is:

1. A.2- Butyne
2. B.2- Butene
3. C.Acetylene
4. D.Ethene

In the reaction, $$\mathrm{C}{\mathrm{H}}_3\mathrm{COOH}\stackrel{\mathrm{LiAl}{\mathrm{H}}_4}{\to }\mathrm{A}\stackrel{\mathrm{PC}{\mathrm{l}}_5}{\to }\mathrm{B}\underset{\mathrm{BaS}{\mathrm{O}}_4}{\overset{Alc.KOH}{\to }}\mathrm{C},$$ the product C is:

1. A.Ethylene
2. B.Acetyl chloride
3. C.Acetaldehyde
4. D.Acetylene

1. A.(I) and (V)
2. B.(II) and (V)
3. C.(I) and (IV)
4. D.(V) and (VI)

1. A.1,2-Propoxide
2. B.Propylene oxide
3. C.1,2-Oxo propane
4. D.1,2-Epoxy propane

Out of the following, the alkene that exhibits optical isomerism is

1. A.3–methyl–2–pentene
2. B.4–methyl–1–pentene
3. C.3–methyl–1–pentene
4. D.2–methyl–2–pentene

The IUPAC name of neopentane is

1. A.2-methylbutane
2. B.2, 2-dimethylpropane
3. C.2-methylpropane
4. D.2,2-dimethylbutane

Arrange the carbanions, $(C{H}_3{)}_3\overline{C}$, $\overline{C}C{l}_3$, $(C{H}_3{)}_2\overline{C}H$, $C_6{H}_5\overline{C}{H}_2$ in order of their decreasing stability :

1. A.$(C{H}_3{)}_2\overline{C}H>\overline{C}C{l}_3>C_6{H}_5\overline{C}{H}_2>(C{H}_3{)}_3\overline{C}$
2. B.$\overline{C}C{l}_3>C_6{H}_5\overline{C}{H}_2>(C{H}_3{)}_2\overline{C}H>(C{H}_3{)}_3\overline{C}$
3. C.$(C{H}_3{)}_3\overline{C}>(C{H}_3{)}_2\overline{C}H>C_6{H}_5\overline{C}{H}_2>\overline{C}C{l}_3$
4. D.$C_6{H}_5\overline{C}{H}_2>\overline{C}C{l}_3>(C{H}_3{)}_3\overline{C}>(C{H}_3{)}_2\overline{C}H$

The alkene that exhibits geometrical isomerism is :

1. A.propene
2. B.2-methyl propene
3. C.2-butene
4. D.2- methyl -2- butene

Which of the following has an optical isomer ?

1. A.$[\mathrm{Co}(\mathrm{en})(\mathrm{N}{\mathrm{H}}_3{)}_2{]}^{2+}$
2. B.$[\mathrm{Co}({\mathrm{H}}_2\mathrm{O}{)}_4(\mathrm{en}){]}^{3+}$
3. C.$[\mathrm{Co}(\mathrm{en}{)}_2(\mathrm{N}{\mathrm{H}}_3{)}_2{]}^{3+}$
4. D.$[\mathrm{Co}(\mathrm{N}{\mathrm{H}}_3{)}_3\mathrm{Cl}{]}^{+}$

Which of the following pairs represents linkage isomers ?

1. A.$[\mathrm{Pd}(\mathrm{PP}{\mathrm{h}}_3{)}_2(\mathrm{NCS}{)}_2]$ and $[\mathrm{Pd}(\mathrm{PP}{\mathrm{h}}_3{)}_2(\mathrm{SCN}{)}_2]$
2. B.$[\mathrm{Co}(\mathrm{N}{\mathrm{H}}_3{)}_5\mathrm{N}{\mathrm{O}}_3]\mathrm{S}{\mathrm{O}}_4$ and $[\mathrm{Co}(\mathrm{N}{\mathrm{H}}_3{)}_5\mathrm{S}{\mathrm{O}}_4]\mathrm{N}{\mathrm{O}}_3$
3. C.$[\mathrm{PtC}{\mathrm{l}}_2(\mathrm{N}{\mathrm{H}}_3{)}_4]\mathrm{B}{\mathrm{r}}_2$ and $[\mathrm{PtB}{\mathrm{r}}_2(\mathrm{N}{\mathrm{H}}_3{)}_4]\mathrm{C}{\mathrm{l}}_2$
4. D.$[\mathrm{Cu}(\mathrm{N}{\mathrm{H}}_3{)}_4][\mathrm{PtC}{\mathrm{l}}_4]$ and $[\mathrm{Pt}(\mathrm{N}{\mathrm{H}}_3{)}_4][\mathrm{CuC}{\mathrm{l}}_4]$

The increasing order of stability of the following free radicals is

1. A.$(C_6{H}_5{)}_2\dot{C}H<(C_6{H}_5{)}_3\dot{C}<(C{H}_3{)}_3\dot{C}<(C{H}_3{)}_2\dot{C}H$
2. B.$(C{H}_3{)}_2\dot{C}H<(C{H}_3{)}_3\dot{C}<(C_6{H}_5{)}_2\dot{C}H<(C_6{H}_5{)}_3\dot{C}$
3. C.$(C{H}_3{)}_2\dot{C}H<(C{H}_3{)}_3\dot{C}<(C_6{H}_5{)}_3\dot{C}<(C_6{H}_5{)}_2\dot{C}H$
4. D.$(C_6{H}_5{)}_3\dot{C}<(C_6{H}_5{)}_2\dot{C}H<(C{H}_3{)}_3\dot{C}<(C{H}_3{)}_2\dot{C}H$

$\mathrm{C}{\mathrm{H}}_3\mathrm{Br}+\mathrm{N}{\mathrm{u}}^{-}\to \mathrm{C}{\mathrm{H}}_3\text{-}\mathrm{Nu}+\mathrm{B}{\mathrm{r}}^{-}$ The decreasing order of the rate of the above reaction with nucleophiles ($\mathrm{N}{\mathrm{u}}^{-}$) A to D is [$\mathrm{N}{\mathrm{u}}^{-}=\text{(A)}\mathrm{Ph}{\mathrm{O}}^{-},\text{(B)}\mathrm{Ac}{\mathrm{O}}^{-},\text{(C)}\mathrm{H}{\mathrm{O}}^{-},\text{(D)}\mathrm{C}{\mathrm{H}}_3{\mathrm{O}}^{-}$]

1. A.$\mathrm{A}>\mathrm{B}>\mathrm{C}>\mathrm{D}$
2. B.$\mathrm{B}>\mathrm{D}>\mathrm{C}>\mathrm{A}$
3. C.$\mathrm{D}>\mathrm{C}>\mathrm{A}>\mathrm{B}$
4. D.$\mathrm{D}>\mathrm{C}>\mathrm{B}>\mathrm{A}$

Increasing order of stability among the three main conformations (i.e. Eclipse, Anti, Gauche) of 2- fluoroethanol is

1. A.Eclipse, Gauche, Anti
2. B.Gauche, Eclipse, Anti
3. C.Eclipse, Anti, Gauche
4. D.Anti, Gauche, Eclipse

In the transformation of ${}_{92}^{238}U$ to ${}_{92}^{234}U$, if one emission is an $\alpha$-particle, what should be the other emission(s)?

1. A.Two ${\beta }^{-}$
2. B.Two ${\beta }^{-}$ and one ${\beta }^{+}$
3. C.One ${\beta }^{-}$ and one $\gamma$
4. D.One ${\beta }^{+}$ and One ${\beta }^{-}$

Reaction of trans-2-phenyl-1-bromocyclopentane on reaction with alcoholic KOH produces

1. A.4-phenylcyclopentene
2. B.2-phenylcyclopentene
3. C.1-phenylcyclopentene
4. D.3-phenylcyclopentene

1. A.3-bromo - 1-chlorocyclohexene
2. B.1-bromo - 3-chlorocyclohexene
3. C.2-bromo - 6-chlorocyclohex - 1 -ene
4. D.6-bromo - 2 - chlorocyclohexene

1. A.
2. B.
3. C.
4. D.

Due to the presence of an unpaired electron, free radicals are:

1. A.Chemically reactive
2. B.Chemically inactive
3. C.Anions
4. D.Cations

Of the five isomeric hexanes, the isomer which can give two monochlorinated compounds is

1. A.n-hexane
2. B.2, 3-dimethylbutane
3. C.2,2-dimethylbutane
4. D.2-methylpentane

Which types of isomerism is shown by 2,3-dichlorobutane?

1. A.Diastereo
2. B.Optical
3. C.Geometric
4. D.Structural

Which of the following compounds shows optical isomerism?

1. A.$[\mathrm{Cu}(\mathrm{N}{\mathrm{H}}_3{)}_4{]}^{+2}$
2. B.$[\mathrm{ZnC}{\mathrm{l}}_4{]}^{-2}$
3. C.$[\mathrm{Cr}({\mathrm{C}}_2{\mathrm{O}}_4{)}_3{]}^{-3}$
4. D.$[\mathrm{Co}(\mathrm{CN}{)}_6{]}^{-3}$

1. A.$(C),(B),(A),(D)$
2. B.$(B),(C),(A),(D)$
3. C.$(D),(C),(B),(A)$
4. D.$(A),(B),(C),(D)$

The correct order of the thermal stability of hydrogen halides (H – X) is :

1. A.HI > HBr > HCl > HF
2. B.HF > HCl > HBr > HI
3. C.HCl < HF > HBr < HI
4. D.HI > HCl < HF < HBr

Which of the following will have meso-isomer also?

1. A.2-chlorobutane
2. B.2-hydroxypropanoic acid
3. C.2,3-dichloropentane
4. D.2,3-dichlorobutane

Which of the following compound is not chiral?

1. A.1- chloropentane
2. B.3-chloro-2- methyl pentane
3. C.1-chloro -2- methyl pentane
4. D.2- chloropentane