General Organic Chemistry & Isomerism · JEE Main previous year questions

An organic compound 'A' ${\mathrm{C}}_4{\mathrm{H}}_8$ on treatment with $\mathrm{KMn}{\mathrm{O}}_4/{\mathrm{H}}^{+}$ yields compound 'B' ${\mathrm{C}}_3{\mathrm{H}}_6\mathrm{O}$. Compound 'A' also yields compound 'B' on ozonolysis. Compound 'A' is :

1. A.2-Methylpropene
2. B.1-Methylcyclopropane
3. C.But-2-ene
4. D.Cyclobutane

[structure: cis-but-2-ene, ${\mathrm{H}}_3\mathrm{C}$ and H on each alkene carbon with both $\mathrm{C}{\mathrm{H}}_3$ on the same side] $+\mathrm{B}{\mathrm{r}}_2\stackrel{\mathrm{CC}{\mathrm{l}}_4}{\to }$ Product "P" Consider the above chemical reaction. The total number of stereoisomers possible for Product 'P' is ____.

0.8 g of an organic compound was analyzed by Kjeldahl's method for the estimation of nitrogen. If the percentage of nitrogen in the compound was found to be 42%, then ____ mL of 1 M ${\mathrm{H}}_2\mathrm{S}{\mathrm{O}}_4$ would have been neutralized by the ammonia evolved during the analysis.

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

Which of the following molecules does not show stereoisomerism?

1. A.3, 4-Dimethylhex-3-ene
2. B.3-Methylhex-1-ene
3. C.3-Ethylhex-3-ene
4. D.4-Methylhex-1-ene

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

The number of acyclic structural isomers (including geometrical isomers) for pentene are ___________

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

The metal that can be purified economically by fractional distillation method is :

1. A.Fe
2. B.Zn
3. C.Cu
4. D.Ni

An organic compound "A" on treatment with benzene sulphonyl chloride gives compound B. B is soluble in dil. NaOH solution. Compound A is :

1. A.${\mathrm{C}}_6{\mathrm{H}}_5-\underset{\begin{array}{c}|\\ C{H}_3\end{array}}{\mathrm{CH}}-\mathrm{N}{\mathrm{H}}_2$
2. B.${\mathrm{C}}_6{\mathrm{H}}_5-\mathrm{NHC}{\mathrm{H}}_2\mathrm{C}{\mathrm{H}}_3$
3. C.${\mathrm{C}}_6{\mathrm{H}}_5-\mathrm{N}-(\mathrm{C}{\mathrm{H}}_3{)}_2$
4. D.${\mathrm{C}}_6{\mathrm{H}}_5-\mathrm{C}{\mathrm{H}}_2\mathrm{NHC}{\mathrm{H}}_3$

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

The method used for the purification of Indium is :

1. A.zone refining
2. B.vapour phase refining
3. C.liquation
4. D.van Arkel method

Which of the following compounds shows geometrical isomerism?

1. A.2-methylpent-1-ene
2. B.4-methylpent-1-ene
3. C.2-methylpent-2-ene
4. D.4-methylpent-2-ene

In an estimation of bromine by Carius method, $1.6\text{ g}$ of an organic compound gave $1.88\text{ g}$ of $\mathrm{AgBr}$. The mass percentage of bromine in the compound is ______ . (Atomic mass, $\mathrm{Ag}=108$, $\mathrm{Br}=80\mathrm{g}\mathrm{mo}{\mathrm{l}}^{-1}$)

1. A.2-nitro-4-hydroxymethyl-5-amino benzaldehyde
2. B.3-amino-4-hydroxymethyl-5-nitro benzaldehyde
3. C.4-amino-2-formyl-5-hydroxymethyl nitrobenzene
4. D.5-amino-4-hydroxymethyl-2-nitro benzaldehyde

The element that can be refined by distillation is :

1. A.gallium
2. B.nickel
3. C.zinc
4. D.tin

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

1. A.(a) and (b)
2. B.(a), (b) and (c)
3. C.(a) and (c)
4. D.(b) and (d)

1. A.2, 5-dimethyl-6-carboxy-hex-3-enal
2. B.6-formyl-2-methyl-hex-3-enoic acid
3. C.2, 5-dimethyl-5-carboxy-hex-3-enal
4. D.2, 5-dimethyl-6-oxo-hex-3-enoic acid

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

The one that is not expected to show isomerism is :

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

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

The number of chiral centres in penicillin is _________.