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

How the following conversion can be carried out?

Isopropyl alcohol to iodoform

How the following conversion can be carried out?

Aniline to phenylisocyanide

Write the structures of the monomers used for getting the following polymers

Melamine – formaldehyde polymer

Write one difference between Multimolecular colloid and Macromolecular colloid

Write one difference between Sol and Gel

Write one difference between O/W emulsion and W/O emulsion

Give reasons : In stoichiometric defects, NaCl exhibits Schottky defect and not Frenkel defect.

Write the product(s) in the following reactions

Give simple chemical tests to distinguish between the following pairs of compounds :

Propanol and 2-methylpropan-2-ol

Write one difference in Lyophobic sol and Lyophilic sol

Why a solution of [Ni(H₂O)₆]²⁺ is green while a solution of [Ni(CN)₄]²⁻ is colourless? (At. no. of Ni = 28)

Define the following term: 

Colligative properties

Write one difference between α-helix and β-pleated structures of proteins.

Name the reagents used in the following reactions:

Account for the following :

H₂S has lower boiling point than H₂O.

Account for the following :

H₂S has lower boiling point than H₂O.

Account for the following :

Iron on reaction with HCl forms FeCl₂ nd not FeCl₃.

Examine the given defective crystal:

Answer the following questions :
(i) What type of stoichiometric defect is shown by the crystal?
(ii) How is the density of the crystal affected by this defect?
(iii) What type of ionic substances show such defect?

Give one example each of sol and gel.

 Arrange the following increasing order of their boiling point:
CH₃CH₂OH, CH₃CHO, CH₃–O–CH₃