Chemistry

This is a Multiple Choice Questions as classified in NCERT Exemplar

Ans: (D)

Aliphatic and arylalkyl primary amines can be prepared by the reduction of the corresponding nitriles with LiAlH₄

Heating alkyl halide with primary, secondary and tertiary amine can be prepared by reduction of LiAlH4 followed by treatment with water.

Heating alkyl halide with potassium salt of phthalimide followed by hydrolysis produces primary amine. This process is known as Gabriel phthalimide reaction. The number of carbon atoms in the chain of amines of product is same as reactant.

This is a Multiple Answer Type Questions as classified in NCERT Exemplar

The Correct option is c.

In the cyclic structure of glucose or fructose, anomeric carbon is carbon that is close to an oxygen atom. As shown in the structure above, atoms 'a' and 'b' are close to the oxygen atom, and the hydroxyl groups of both carbon atoms have different orientations.

This is a Multiple Choice Questions as classified in NCERT Exemplar

Ans: (B)

Among primary, secondary, and tertiary amines, tertiary amines are the most volatile compounds as they don't have any strong intermolecular H-bonding between N-H like the primary and secondary amines have. 

So due to weak dipole-dipole interactions, (B) will be the most volatile. 

This is a Multiple Answer Type Questions as classified in NCERT Exemplar

The Correct option is a.

In the same way as (+) glyceraldehyde has a group on the lowest asymmetric carbon on the right side, the I, II, and III structures have a (-OH) group on the lowest asymmetric carbon on the right side giving them a D-configuration.

This is a Multiple Choice Questions as classified in NCERT Exemplar

Ans: (A)  

The basic strength of an atom is determined by its electron-donating capacity; in this case, the amide is the most basic due to the presence of a negative charge and two lone pairs of electrons on the nitrogen atom.

This is a Multiple Answer Type Questions as classified in NCERT Exemplar

The Correct option is c.

The absence of a free (-CHO) aldehyde group is indicated by the fact that glucose pentaacetate does not react with hydroxylamine. The open structure of glucose cannot account for this, although the open chain structure of glucose can account for all other features.

This is a Multiple Choice Questions as classified in NCERT Exemplar

Ans: (D) 

Pyrrolidine is the strongest of two bases because the lone pair of nitrogen does not involve sin resonance, and the presence of two alkyl basic compounds increases the basic strength among the given four compounds.

This is a Multiple Answer Type Questions as classified in NCERT Exemplar

Ans: The Correct option is a.

Anomers are cyclic monosaccharide structures that differ structurally at carbon-1. In this scenario, I and II are anomers since they differ only at carbon -1.

This is a Multiple Choice Questions as classified in NCERT Exemplar

Ans:  (D) 

Since phenol is the strongest acid among the four options listed above, it is the weakest Brönsted base. The stronger the acid, the weaker the conjugate base.

Amines have a strong tendency to accept electrons thus they are a strong bronsted base while phenol is the strongest acid among all, therefore as per the relation of conjugative strong acids and weak bases, phenol is the weakest base. 

This is a Multiple Answer Type Questions as classified in NCERT Exemplar

The Correct option is d.

Adenine, guanine, thymine, and cytosine are the four bases found in DNA. As a result, uracil is not found in DNA as we cannot identify it among the other nucleotides that are present in the DNA. Uracil is, however, seen in RNA, another nucleic acid found in most of the organisms.