Science (English Medium) इयत्ता १२ - CBSE Question Bank Solutions for Chemistry

Assertion: Only a small amount of \[\ce{HCl}\] is required in the reduction of nitro compounds with iron scrap and \[\ce{HCl}\] in the presence of steam.

Reason: \[\ce{FeCl2}\] formed gets hydrolysed to release \[\ce{HCl}\] during the reaction.

Assertion: Aromatic 1° amines can be prepared by Gabriel Phthalimide Synthesis.

Reason: Aryl halides undergo nucleophilic substitution with anion formed by phthalimide.

Sucrose (cane sugar) is a disaccharide. One molecule of sucrose on hydrolysis gives ______.

Which of the following statements is not true about glucose?

Carbohydrates are classified on the basis of their behaviour on hydrolysis and also as reducing or non-reducing sugar. Sucrose is a: 

(i) monosaccharide

(ii) disaccharide

(iii) reducing sugar

(iv) non-reducing sugar

How do you explain the presence of all the six carbon atoms in glucose in a straight chain?

In nucleoside a base is attached at 1′ position of sugar moiety. Nucleotide is formed by linking of phosphoric acid unit to the sugar unit of nucleoside. At which position of sugar unit is the phosphoric acid linked in a nucleoside to give a nucleotide?

Under what conditions glucose is converted to gluconic and saccharic acid?

Which sugar is called invert sugar? Why is it called so?

During curdling of milk, what happens to sugar present in it?

How do you explain the presence of five – OH groups in glucose molecule?

How do you explain the presence of an aldehydic group in a glucose molecule?

Which of the following are characteristics of thermosetting polymers?

(i) Heavily branched cross linked polymers.

(ii) Linear slightly branched long chain molecules.

(iii) Become infusible on moulding so cannot be reused.

(iv) Soften on heating and harden on cooling, can be reused.

Which of the following polymers are thermoplastic?

(i) Teflon

(ii) Natural rubber

(iii) Neoprene

(iv) Polystyrene

Which of the following polymers are used as fibre?

(i) Polytetrafluoroethane

(ii) Polychloroprene

(iii) Nylon

(iv) Terylene

Why are rubbers called elastomers?

Can enzyme be called a polymer?

Amongst the following antihistamines, which are antacids?

(i) Ranitidine

(ii) Brompheniramine

(iii) Terfenadine

(iv) Cimetidine

Both antacids and antiallergic drugs are antihistamines but they cannot replace each other. Explain why?

What are the functions performed by histamine in the body?