1

NEET 2021

MCQ (Single Correct Answer)
Dihedral angle of least stable conformer of ethane is :
A
0$$^\circ$$
B
120$$^\circ$$
C
180$$^\circ$$
D
60$$^\circ$$

Explanation

Ethane has two conformers (i) Eclipsed (ii) Staggered

Eclipsed conformer is least stable while staggered conformer is most stable. In eclipsed conformer the dihedral angle is 0$$^\circ$$.
2

NEET 2021

MCQ (Single Correct Answer)
Identify the compound that will react with Hinsberg's reagent to give a solid which dissolves in alkali.
A
B
C
D

Explanation

$$\bullet$$ Benzenesulphonyl chloride (C6H5SO2Cl) is also known as Hinsberg's reagent.

$$\bullet$$The reaction of Hinsberg's reagent (C6H5SO2Cl) with primary amine (CH3CH2NH2) yields N-ethylbenzene sulphonamide.


$$\bullet$$ The reaction of Hinsberg's reagent (C6H5SO2Cl) with secondary amine (C2H5NHCH3) gives, N-Ethyl-N-Methyl benzene sulphonamide


$$\bullet$$ 3$$^\circ$$ amine do not react with Hinsberg reagent.
3

NEET 2020 Phase 1

MCQ (Single Correct Answer)
A tertiary butyl carbocation is more stable than a secondary butyl carbocation because of which of the following?
A
+R effect of $$ - $$ CH3 groups
B
$$ - $$ R effect of $$ - $$ CH3 groups
C
Hyperconjugation
D
$$ - $$ I effect of $$ - $$ CH3 groups

Explanation


More the number of $$\alpha $$$$ - $$ H atoms, more will be the hyper conjugation effect hence more will be the stability of carbocation.
4

NEET 2020 Phase 1

MCQ (Single Correct Answer)
Paper chromatography is an example of :
A
Partition chromatography
B
Thin layer chromatography
C
Column chromatography
D
Adsorption chromatography

Explanation

Paper chromatography is a type of partition chromatography in which a special quality paper known as chromatography paper is used.

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