NCERT Class 12 Chemistry Multiple Choice Questions(MCQs) & Answers NCERT Class 12 Chemistry QUESTIONS

NCERT Class 12 Chemistry Multiple Choice Questions(MCQs) & Answers

21 Trunbull’s blue is

A Ferrous ferricyanide

B Fe3[Fe(CN)6]4

C Ferrous cyanide

D Ferricyanide

Answer: Ferrous ferricyanide

22 Roasted copper pyrites on smelting with sand produces

A FeSiO3 and Cu2S

B Fe3(PO4)2 and Cu2S

C CaSiO2 and Cu2O

D Ca3(PO4)2 and Cu2S

Answer: FeSiO3 and Cu2S

23 Physical adsorption of a gaseous species may change to chemical adsorption with ___________ .

A decrease in temperature

B increase in temperature

C increase in surface area of adsorbent

D decrease in surface area of adsorbent

Answer: increase in temperature

24 When Cl2 reacts with hot and cone. NaOH, the oxidation number of chlorine changes from

A zero to +1 and zero to +5

B 0 to -1 and 0 to +5

C zero to -1 and zero to +3

D 0 to +1 and 0 to -3

Answer: 0 to -1 and 0 to +5

25 The emf of the cell: Ni / Ni2+ (1.0 M) // Au3+ (1.0 M) / Au (E° = -0.25 V for Ni2+/Ni; E° = 1.5 V for Au3+/Au) is

A 1.25 V

B -1.25 V

C 1.75 V

D 2.0 V

Answer: 1.75 V

26 The half life period of first order reaction is 1386 seconds. The specific rate constant of the reaction is

A 0.5 × 10-3 s-1

B 5.0 × 10-3 s-1

C 0.5 × 10-2 s-1

D 5.0 × 10-2 s-1

Answer: 0.5 × 10-3 s-1

27 The rate constant of a reaction A ? B is 0.6 × 103 mole per second. If the concentration of [A] is 5 M, then what will be concentration of [B] after 20 months?

A 3.60 M

B 0.36 M

C 0.72 M

D None of these

Answer: 0.72 M

28 Fluorine differs from rest of the halogens in some of its properties. This is due to

A its smaller size and high electronegativity.

B lack of d-orbitals.

C low bond dissociation energy.

D All of the these.

Answer: lack of d-orbitals.

29 Which of the following ore is best concentrated by froth floatation process?

A Galena

B Malachite

C Magnetic

D Siderite

Answer: Galena

30 Extraction of gold and silver involves leaching with CN–. Silver is later recovered by

A Displacement by Zn

B Liquation

C Distillation

D Zone refining

Answer: Displacement by Zn

NCERT Class 12 Chemistry Multiple Choice Questions(MCQs) & Answers

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