Chemistry

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

Correct options are a and d.

Enzymes are protein molecules that operate as biocatalysts in the body, facilitating chemical processes. The pace of the reaction is accelerated by these catalysts.

This is a Multiple Choice Questions as classified in NCERT Exemplar

Ans: a and b  

In addition to the nitro derivatives, direct nitration of aniline produces tarry oxidation products. Furthermore, aniline is protonated in the strongly acidic medium to form the anilinium ion, which is meta directing. As a result, in addition to the ortho and para derivatives, a significant amount of meta derivative is formed.

However, by protecting the? NH₂ group with an acetylation reaction with acetic anhydride, the nitration reaction can be controlled and the p-nitro derivative obtained as the main product.

This is a Multiple Choice Questions as classified in NCERT Exemplar

Ans: option a and c

(a) Primary alkyl halides react with ammonia to give primary amines. Correct reaction.

(B) Elimination process doesn't occur with aq. KOH, hydrolysis process takes place. (B) is incorrect. 

(c) Dehydrohalogenation I.e. elimination of HCl occurs which produces alkene as the product takes place with alc. KOH . (c) is correct.

(d) In this reaction, aliphatic primary amines, on treatment with nitrous acid, produce primary alcohol as a product.

Therefore (d) is incorrect. 

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

Correct options are a and b.

Purines are made up of a six-membered nitrogen-containing ring joined with a five-membered nitrogen-containing ring.

Purine bases are guanine and adenine, while pyrimidine bases are thymine and uracil.

 

Hence (a) and (b) are correct choices for this question.

This is a Multiple Choice Questions as classified in NCERT Exemplar

Ans: (a and b) 

Gabriel synthesis is a method for producing primary amines. When phthalimide is treated with ethanolic potassium hydroxide, it forms a potassium salt of phthalimide, which when heated with an alkyl halide and then alkaline hydrolyzed yields the corresponding primary amine.

This is a Multiple Choice Questions as classified in NCERT Exemplar

Ans: A, B & C  

As the NH₂ group is Ortho para directing group, so Br⁺ attacks only at the o and p positions thus the products formed corresponds to the option A, B and C.

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

Correct options are b and d.

Fibrous protein is generated when the polypeptide chain runs parallel and is held together by hydrogen and disulphide bonds.

This is a Multiple Choice Questions as classified in NCERT Exemplar

Ans: Option a and b

NHCOCH₃ is an ortho- para directing group so ortho-para products are formed. 

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

Correct options are a and c.

The cyclic structure of ribose and fructose is five-membered (furanose structures). Like compound furans, they have a five-membered ring.

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

Correct options are a, b and c.

Lysine is an amino acid with the structural formula of (a).

(b) Because the number of groups (two) is more than the number of -COOH groups (one), it is a basic amino acid (one).

Because it is created in human bodies, it is a non-essential amino acid.