CBSE Class 12 Chemistry Solutions MCQs Set 03

Question: The atmospheric pollution is generally measured in the units of
(a) mass percentage
(b) volume percentage
(c) volume fraction
(d) ppm

Answer : D

Question: Among the following substances the lowest vapour pressure is exerted by
(a) water
(b) alcohol
(c) ether
(d) mercury

Answer : D

Question: Which has the lowest boiling point at 1 atm pressure?
(a) 0.1 M KCl
(b) 0.1 M Urea
(c) 0.1 M CaCl₂
(d) 0.1 M A1Cl₃

Answer : B

Question: Value of Henry’s constant KH _.
(a) increases with increase in temperature.
(b) decreases with increase in temperature.
(c) remains constant.
(d) first increases then decreases.

Answer : A

Question: Osmotic pressure of a solution is 0.0821 atm at a temperature of 300 K. The concentration in moles/litre will be
(a) 0.33
(b) 0.666
(c) 0.3 × 10^-2
(d) 3

Answer : C

Question: The van’t Hoff factor (i) accounts for
(a) degree of solubilisation of solute.
(b) the extent of dissociation of solute.
(c) the extent of dissolution of solute.
(d) the degree of decomposition of solution.

Answer : B

Question: Which of the following possesses the physical state of solute and solvent liquid and solid respectively?
(a) solutions of sugar in water
(b) zinc amalgam
(c) solutions of Naphthalene in benzene
(d) brass

Answer : B

Question: Which of the following is not correctly matched?
(a) Solutions of hydrogen and palladium: Gaseous solute in a solid solvent
(b) Sodium amalgam: Liquid solute in a solid solvent
(c) Solution of camphor and nitrogen: Solid solute in Gaseous solvent
(d) Solution of chloroform and nitrogen: Gaseous solute in Gaseous solvent

Answer : D

Question: Which of the following is an example of a solid solution?
(a) Interstitial compound of hydrogen and Pd
(b) WC
(c) Zn/Hg
(d) All of these

Answer : D

Question: 2.5 g of ethanoic acid (CH₃ COOH) is dissolved in 75 g of benzene, Calculate the molality of the solution.
(a) 3.5 m
(b) 0.8 m
(c) 0.556 m
(d) 0.180 m

Answer : C

Question: The amount of water required to make 10% ethanol in a water solution using 10 mL of pure ethanol is:
(a) 90 mL
(b) 50 mL
(c) 30 mL
(d) 60 mL

Answer : A

Question: What mass of ethanol be added to 1.0 kg water to have the mole fraction of ethanol equal to 0.20?
(a) 63.89 g
(b) 638.89 g
(c) 6.39 g
(d) 683.89 g

Answer : B

Question: What weight of glycerol should be added to 600 g of water in order to lower its freezing point by 10°C ?
(a) 496 g
(b) 297 g
(c) 310 g
(d) 426 g

Answer : B

Question: Maximum amount of a solid solute that can be dissolved in a specified amount of a given liquid solvent does not depend upon ________.
(a) Temperature
(b) Nature of solute
(c) Pressure
(d) Nature of solvent

Answer : C

Question: What is the mole fraction of the solute in a 1.00 m aqueous solution?
(a) 0.0177
(b) 0.177
(c) 1.770
(d) 0.0354

Answer : A

Question: A solution containing 10.2 g glycerine per litre is isotonic with a 2% solution of glucose. What is the molecular mass of glycerine?
(a) 91.8 g
(b) 1198 g
(c) 83.9 g
(d) 890.3 g

Answer : A

Question: What is the mole fraction of the solute in a 2.5 m aqueous solution?
(a) 8.0
(b) 0.99
(c) 0.10
(d) 0.043

Answer : D

Question: How much oxygen is dissolved in 100 rnL water at 298 K if partial pressure of oxygen is 0.5 atm and K = 1.4 × 10^-3 mol/L/atm?
(a) 22.4 mg
(b) 22.4 g
(c) 2.24 g
(d) 2.24 mg

Answer : D

Question: Vapour pressure of a pure liquid X is 2 atm at 300 K. It is lowered to 1 atm on dissolving 1 g of Y in 20 g of liquid X. If molar mass of X is 200, what is the molar mass of Y?
(a) 20
(b) 50
(c) 100
(d) 200

Answer : B

Question: Sprinkling of salt helps in clearing the snow covered roads in hills. The phenomenon involved in the process is
(a) lowering in vapour pressure of snow
(b) depression in freezing point of snow
(c) melting of ice due to increase in temperature by putting salt
(d) increase in freezing point of snow

Answer : B

Question: The molarity of an aqueous solution of NaOH containing 8 g in 2 litre of the solution is:
(a) 0.15 M
(b) 0.2 M
(c) 0.25 M
(d) 0.15 M

Answer : A

Question: 10% w/w NaOH solution. Find molality.
(a) 1.5
(b) 1.2
(c) 2.2
(d) 2.778

Answer : D

Question: Molarity of liquid HCl will be, if density of solution is 1.17 gm/cc
(a) 36.5
(b) 32.05
(c) 18.25
(d) 42.10

Answer : B

Question: 234.2 gm of sugar syrup contains 34.2 gm of sugar. What is the molal concentration of the solution.
(a) 0.1
(b) 0.5
(c) 5.5
(d) 55

Answer : B

Question: Concentrated sulphuric acid is approximately 18 molar. 5 cc of it are added to make 500 cc of the solution. The approx. normality of the solution will be:
(a) 0.18
(b) 0.009
(c) 0.36
(d) 0.27

Answer : C

Question: 10 mL of 0.2M KNO₃ mixed with 15 mL 0.3M NaNO₃ and the total volume was made at 50mL. The final molarity of the nitrate ions in the solutions is:
(a) 0.13 M
(b) 0.23 M
(c) 0.75 M
(d) 1.25 M

Answer : A

Question: The amount of oxalic acid (mol wt. 63) required to prepare 500 mL of its 0.10 N solution is:
(a) 0.315 g
(b) 3.150 g
(c) 6.300 g
(d) 63.00 g

Answer : B

Question: The mass by volume percentage composition (w/V) of 2M aqueous solution of glucose is:
(a) 3.6
(b) 18
(c) 360
(d) 36

Answer : D

Question: Which of the following given compounds is least soluble in water?
(a) Hexan-1-ol
(b) Glycerol
(c) Propane-1,3-diol
(d) Ethylene glycol

Answer : A

Question: Henry’s law constant for molality of methane is benzene at 298 K is 4.27 × 105 mm Hg. The mole fraction of methane in benzene at 298 K under 760 mm Hg is
(a) 1.78 × 10^-3
(b) 17.43
(c) 0.114
(d) 2.814

Answer : A