CBSE XII Chemistry practice questions

Question 1

Which of the following concentration terms is independent of temperature?

Accepted Answer

Molality

Answer

Molarity

Answer

Normality

Answer

Formality

Question 2

According to Kohlrausch's law, the limiting molar conductivity of CH3COOH can be determined using the limiting molar conductivities of:

Accepted Answer

CH3COONa, HCl, and NaCl

Answer

CH3COOK, NaCl, and HBr

Answer

NaCl, KCl, and NaOH

Answer

CH3COONa, NaOH, and NaCl

Question 3

In the Arrhenius equation k = A * exp(-Ea / RT), the factor exp(-Ea / RT) corresponds to the:

Accepted Answer

Fraction of molecules having kinetic energy equal to or greater than Ea

Answer

Total number of colliding molecules

Answer

Activation energy of the reaction

Answer

Orientation factor (steric factor)

Question 4

Which of the following lanthanoid ions is commonly used as a strong oxidizing agent in volumetric analysis (exhibiting +4 oxidation state)?

Accepted Answer

Ce^4+

Answer

Eu^2+

Answer

Yb^2+

Answer

Gd^3+

Question 5

What is the oxidation state and coordination number of Cobalt in K[Co(CO)4]?

Accepted Answer

-1 and 4

Answer

+1 and 4

Answer

0 and 4

Answer

+3 and 6

Question 6

When anisole (methoxybenzene) is treated with HI at 373 K, the products formed are:

Accepted Answer

Phenol and Iodomethane (CH3I)

Answer

Iodobenzene and Methanol

Answer

Benzyl iodide and Water

Answer

Phenol and Ethanol

Question 7

Reduction of benzoyl chloride (C6H5COCl) with H2 in the presence of Pd supported on BaSO4 gives benzaldehyde. This reaction is called:

Accepted Answer

Rosenmund reduction

Answer

Stephen reaction

Answer

Etard reaction

Answer

Clemmensen reduction

Question 8

Gabriel phthalimide synthesis is exclusively used for the preparation of pure:

Accepted Answer

Primary aliphatic amines

Answer

Primary aromatic amines (Aniline)

Answer

Secondary amines

Answer

Tertiary amines