BITSAT Chemistry Solutions MCQs

Question: Raoult’s law becomes a special case of Henry’s law when

a)

b)

c)

d)

Answer:

Question: Identify the correct order of solubilty of Na₂S. CuS and ZnS in aqueous medium

a) CuS > ZnS > Na₂S

b) ZnS > Na₂S > CuS

c) Na₂S > CuS > ZnS

d) Na₂S > ZnS > CuS

Answer: Na₂S > ZnS > CuS

Question: Equal weights of NaCl and KCl are dissolved separately in equal volumes of solutions. Molarity of the two solutions will be :

a) Equal

b) That of NaCl will be less than that of KCl

c) That of NaCl will be more than that of KCl solution

d) That of NaCl will be about half of that of KCl solution

Answer: That of NaCl will be more than that of KCl solution

Question: The van’t Hoff factor i for an electrolyte which undergoes dissociation and association in solvents are respectively

a) Greater than 1 and greater than 1

b) Less than 1 and greater than 1

c) Less than 1 and less than 1

d) Greater than 1 and less than 1

Answer: Greater than 1 and less than 1

Question: Which of the following metal sulphides has maximum solubility in water?

a) HgS K_sp = 10–54

b) CdS K_sp = 10^–30

c) FeS K_sp = 10^–20

d) ZnS K_sp = 10^–22

Answer: FeS K_sp = 10^–20

Question: 1.00 g of a non-electrolyte solute (molar mass 250 g mol^–1) was dissolved in 51.2 g of benzene. If the freezing point depression constant, K_f of benzene is 5.12 K kg mol^–1, the freezing point of benzene will be lowered by

a) 0.3 K

b) 0.5 K

c) 0.4 K

d) 0.2

Answer: 0.4 K

Question: Coolant used in car radiator is aqueous solution of ethylene glycol. In order to prevent the solution from freezing at – 0.3°C. How much ethylene glycol must be added to 5 kg of water ? (K_f = 1.86 K Kg mol^–1)

a) 50 g

b) 55 g

c) 45 g

d) 40 g

Answer: 55 g

Question: Which one of the following statements is FALSE?

a) The correct order of osmotic pressure for 0.01 M aqueous solution of each compound is BaCl₂ > KCl > CH₃COOH > sucrose

b) The osmotic pressure (π) of a solution is given by the equation π = MRT, where M is the molarity of the solution

c) Raoult’s law states that the vapour pressure of a component over a solution is proportional to its mole fraction

d) Two sucrose solutions of same molality prepared in different solvents will have the same freezing point depression

Answer: Two sucrose solutions of same molality prepared in different solvents will have the same freezing point depression

Question:  The degree of dissociation of Ca(NO₃)₂ in dilute aq. solution containing 7.0 g of salt per 100 g of water at 100° C is 70%. If vapour pressure of water at 100° C is 760 mm. The vapour pressure of solution is

a) 735

b) 730

c) 760

d) 746

Answer: 746

Question: The volume of water added to 500 ml 0.5 M NaOH so that its strength becomes 10 mg NaOH per ml is :

a) 100 ml

b) 200 ml

c) 250 ml

d) 500 ml

Answer: 500 ml

Question: In a 0.2 molal aqueous solution of a weak acid HX the degree of ionization is 0.3. Taking k_f for water as 1.85, the freezing point of the solution will be nearest to

a) – 0.360º C

b) – 0.260º C

c) + 0.480º C

d) – 0.480º C

Answer: – 0.480º C

Question: The milliequivalent in 60 ml 4M H₂SO₄ is :

a) 240

b) 480

c) 24

d) 48

Answer: 480

Question: The heat of vaporisation of benzene is 7353 cal mol^–1. The approximate bpt. of benzene is

a) 77.1° C

b) 87.1° C

c) 101° C

d) 95° C

Answer: 77.1° C

Question: Which of the following solution will have lowest boiling point

a) 0.1M NaCl

b) 0.1M KCl

c) 0.1M CaCl₂

d) 0.1M glucose

Answer: 0.1M glucose

Question: An X molal solution in carbon tetrachloride has the mole fraction of solute equal to 0.23527 . The value of X is

a) 1.55

b) 1.82

c) 2.00

d) 2.16

Answer: 2.00

Question: Which of the following solutions will have the highest boiling point?

a) 0.5 molal BaCl₂

b) 1.0 molal KBr

c) 1.8 × 1024 glucose molecules per litre.

d) 100 g powdered glucose in one litre water

Answer: 1.8 × 1024 glucose molecules per litre.

Question: To neutralise completely 20 mL of 0.1 M aqueous solution of phosphorous acid (H₃PO₃), the value of 0.1 M aqueous KOH solution required is

a) 40 mL

b) 20 mL

c) 10 mL

d) 60 mL

Answer: 40 mL

Question: The volume of water added to 500 ml 0.5 M NaOH so that its strength becomes 10 mg NaOH per ml is :

a) 100 ml

b) 200 ml

c) 250 ml

d) 500 ml

Answer: 500 ml

Question: Which of the following metal sulphides has maximum solubility in water?

a) HgS K_sp = 10^–54 

b) CdS K_sp = 10^–30

c) FeS K_sp = 10^–20

d) ZnS K_sp = 10^–22

Answer: FeS K_sp = 10^–20

Question: Equal weights of NaCl and KCl are dissolved separately in equal volumes of solutions. Molarity of the two solutions will be :

a) Equal

b) That of NaCl will be less than that of KCl

c) That of NaCl will be more than that of KCl solution

d) That of NaCl will be about half of that of KCl solution

Answer: That of NaCl will be more than that of KCl solution