Science (English Medium) कक्षा १२ - CBSE Question Bank Solutions

Arrange the following polymers in increasing order of their intermolecular forces.

(i) Nylon 6, 6, Buna-S, Polythene.

(ii) Nylon 6, Neoprene, Polyvinyl chloride.

In which classes, the polymers are classified on the basis of molecular forces?

Define thermoplastics with two examples of each.

Define thermosetting polymers with two examples of them.

Enumerate the reactions of D-glucose which cannot be explained by its open chain structure.

Write a short note on the following:

Hoffmann’s bromamide reaction

Accomplish the following conversion:

Nitrobenzene to benzoic acid

Accomplish the following conversion:

Benzyl chloride to 2-phenylethanamine

Accomplish the following conversion:

Benzamide to toluene

Give the structure of A, B and C in the following reaction:

\[\ce{CH3CH2I ->[NaCN] A ->[OH-][Partial hydrolysis] B ->[NaOH + Br2] C}\]

Give the structure of A, B and C in the following reaction:

\[\ce{C6H5N2Cl ->[CuCN] A ->[H2O/H+] B ->[NH3][\Delta] C}\]

Give the structure of A, B and C in the following reaction:

\[\ce{CH3CH2Br ->[KCN] A ->[LiAlH4] B ->[HNO2][0^\circ C] C}\]

Give the structure of A, B and C in the following reaction:

\[\ce{C6H5NO2 ->[Fe/HCl] A ->[NaNO2 + HCl][273 K] B ->[H2O/H+][\Delta] C}\]

Give the structures of A, B and C in the following reaction:

\[\ce{CH3COOH ->[NH3][\Delta] A ->[NaOBr] B ->[NaNO2/HCl] C}\]

Give the structures of A, B and C in the following reaction:

\[\ce{C6H5NO2 ->[Fe/HCl] A ->[HNO2][273 K] B ->[C6H5OH] C}\]

Why cannot aromatic primary amines be prepared by Gabriel phthalimide synthesis?

Write the reaction of aromatic primary amine with nitrous acid.

Write the reaction of aliphatic primary amine with nitrous acid.

Give a plausible explanation for the following:

Why are amines less acidic than alcohols of comparable molecular masses?

Write the structure of the product of the following reaction:

\[\ce{H3C - C ≡ C - H ->[Hg^{2+}, H2SO4]}\]