NCERT MCQ CLASS-12 CHAPTER-2 | CHEMISTRY NCERT MCQ | SOLUTIONS CLASS | EDUGROWN

In This Post we are  providing Chapter-2 Solutions Class NCERT MCQ for Class 12 Chemistry which will be beneficial for students. These solutions are updated according to 2021-22 syllabus. These MCQS  can be really helpful in the preparation of Board exams and will provide you with a brief knowledge of the chapter.

NCERT MCQ ON SOLUTIONS CLASS

Question 1 : An aqueous solution of hydrochloric acid

a) Obeys Raoult’s law
b) Shows negative deviation from Raoult’s law
c) Shows positive deviation from Raoult’s law
d) Obeys Henry’s law at all compositions

Answer : B

Question 2 :12g of urea is dissolved in 1 liter of water and 68.4 g of sucrose is dissolved in 1 liter of water. The lowering of vapor pressure of first case is

a) equal to second
b) greater than second
c) less than second
d) double that of second

Answer : A

Question 3 : At a particular temperature, the vapor pressures of two liquids A and B are respectively 120 and 180 mm of mercury. If 2 moles of A and 3 moles of B are mixed to form an ideal solution, the vapor pressure of the solution at the same temperature will be (in mm of mercury)

a) 156

b) 145
c) 150

d) 108

Answer : A

Question 4 : The freezing point of equimolar aqueous solution will be highest for

a) C₆H₅NH₃ ⁺Cl^–   b) Ca(NO₃)₂
c) La(NO₃)₂         d) C₆H₁₂O₆

Answer : D

Question 5: Which of the following 0.10 m aqueous solutions will have the lowest freezing point ?

a) Al₂(SO₄)₃

 b) C₆H₁₂O₆
c) KCl  

d) C₁₂H₂₂O₁₁

Answer : A

Question 6 : A solution containing 10g per dm³ of urea (molecular mass = 60 gmol^–1) is isotonic with a 5% solution of a non volatile solute. The molecular mass of this non volatile solute is

a) 300 g mol^–1

 b) 350 g mol^–1
c) 200 g mol^–1

 b) 250 g mol^–1

Answer : A 

Question 7: The vapor pressure of a solvent decreases by 10 mm of Hg when a non-volatile solute was added to the solvent. The mole fraction of the solute in the solution is 0.2. What should be the mole fraction of the solvent if the decrease in
the vapor pressure is to be 20 mm of Hg ?

a) 0.8

b) 0.6
c) 0.4

d) 0.2

Answer : B

Question 8 : A solution containing 1.8 g of a compound (empirical formula CH₂O) in 40 g of water is observed to freeze at –0.465° C. The molecular formula of the compound is (K_f of water = 1.86 kg K mol^–1)

a) C₂H₄O₂ 

b) C₃H₆O₃
c) C₄H₈O₄ 

d) C₆H₁₂O₆

Answer : D

Question 9 : Which observation(s) reflect(s) colligative properties?
(i) A 0.5 m NaBr solution has a higher vapor pressure than a 0.5 m BaCl₂ solution at the same temperature
(ii) Pure water freezes at the higher temperature than pure methanol
(iii) a 0.1 m NaOH solution freezes at a lower temperature than pure water

Choose the correct answer from the codes given below

a) (i), (ii) and (iii) b) (i) and (ii)
c) (ii) and (iii)       d) (i) and (iii)

Answer : D

Question 10 : The vapor pressure of benzene at 30°C is 121.8 mm. By adding 15 g of non-volatile solute in 250 g of benzene, its vapor pressure is decreased to 120.2 mm. The molecular weight of solute is :

a) 156.6 g

b) 267.4 g
c) 356.3 g

d) 467.4 g

Answer : C

Question 11: Pure benzene freezes at 5.45°C. A 0.374 m solution of tetrachloroethane in benzene freezes at 3.55°C. The Kf for benzene is:

a) 0.508

b) 5.08
c) 50.8  

d) 508

Answer : B

Question 12 : 0.450 g of urea (mol.wt.60) in 22.5 g of water show 0.170°C of elevation in boiling point. The molal elevation constant of water is:

a) 0.051°C

b) 0.51°C
c) 5.1°C  

d) 0.83°C

Answer : B

Question 13 : The colligative property is not represented by :

a) elevation in boiling point
b) osmotic pressure
c) optical activity
d) relative lowering of vapour pressure

Answer : C

Question 14 : 20 g of a substance were dissolved in 500 mL of water and the osmotic pressure of the solution was found to be 600 mm of mercury at 15°C. The molecular weight of substance is :

a) 998 

b) 1028
c) 1098

d) 1198

Answer : D

Question 15 : Which one of the statements given below concerning properties of solutions, describes a colligative effect?

a) Boiling point of pure water decreases by the addition of ethanol
b) Vapour pressure of pure water decreases by the addition of nitric acid
c) Vapour pressure of pure benzene decreases by the addition of naphthalene
d) Boiling point of pure benzene increases by the addition of toluene

Answer : C