CBSE Class 12 Chemistry Solutions MCQs Set J

Question: A binary liquid solution is prepared by mixing n-heptane and ethanol. Which one of the following statements is correct regarding the behaviour of the solution ? 
a) The solution formed is an ideal solution
b) The solution is non-ideal, showing positive deviation from Raoult’s law
c) The solution is non-ideal, showing negative deviation from Raoult’s law
d) n-heptane shows positive deviation while ethanol show negative deviation from Raoult’s law
Answer: b

Question: Vapour pressure of pure ‘A’ is 70 mm of Hg at 25°C. It fom1s an ideal solution with ‘B’ in which mole fraction of A is 0.8. If the vapour pressure of the solution is 84 mm of Hg at 25°C, the vapour pressure of pure ‘B’ at 25°C is
a) 28 mm
b) 56 mm 
c) 70 mm
d) 140 mm
Answer: d

Question: A mixture of ethyl alcohol and propyl alcohol has a vapour pressure of 290 mm at 300 K The vapour pressure of propyl alcohol is 200 mm. If the mole fraction of ethyl alcohol is 0.6, its vapour pressure (in mm) at the same temperature will be 
a) 350
b) 300
c) 700
d) 360
Answer: a

Question: The volume of 10 N and 4 N HCI required to make 1 L of 7 N HCI are 
a) 0.50 L of 10 N HCI and 0.50 L of 4 N HCI
b) 0.60 L of 10 N HCI and 0.40 L of 4 N HCI
c) 0.80 L of 10 N HCI and 0.20 L of 4 N HCI
d) 0.75 L of 10 N HCI and 0.25 L of 4 N HCI
Answer: a

Question: A solution contains 1. 2046 x 10²⁴ hydrochloric acid molecules in 1 dm³ of the solution. The strength of the solution is 
a) 6 N
b) 2 N
c) 4 N
d) 8 N
Answer: b

Question: 35.4 mL of HCI is required for the neutralisation of a solution containing 0.275 g of sodium hydroxide. The normality of hydrochloric acid is 
a) 0.97N
b) 0.142N
c) 0.194N
d) 0.244N
Answer: c

Question: One part of solute expressed as in one million parts of solvent is
a) ppm
b) mg/100 cc
c) g/L
d) g/100 cc
Answer: a

Question: The molarity of the solution obtained by dissolving 2.5g of NaCl in 100 mL of water is 
a) 0.00428 moles
b) 428 moles
c) 0.428 moles
d) 0.0428 moles
Answer: c

Question: Which one is correct? 
a) Molality changes with temperaure
b) Molality does not change with temperature.
c) Molarity does not change with temperature.
d) Normality does not change with temperature.
Answer: b

Question: Volume of water needed to mix with 10 mL solution of 1 N HCI to get 0.1 N HCI is
a) 900 mL
b) 9 mL
c) 90 mL
d) 100 mL
Answer: c

Question: Find the molarity of the solution containing 5.3 g of Na₂CO₃ in 500 mL solution
a) 1.0 M
b) 0.1 M
c) 0.25 M
d) 0.2 M
Answer: b

Question: What is the molarity of 0.2 N Na₂CO₃ solution?
a) 0.1 M
b) 0 M
c) 0.4 M
d) 0.2 M
Answer: a

Question: The molarity of a solution obtained by mixing 750 mL of 0.5 M HCl with 250 mL of 2 M HCl will be
a) 0.875 M
b) 1.00 M
c) 1.75 M
d) 0.0975 M
Answer: a

Question: Equal moles of water and urea are taken in a flask. What is mass percentage of urea in the solution?
a) 23.077%
b) 230.77%
c) 2.3077%
d) 0.23077%
Answer: a

Question: What is molarity of K+ in aqueous solution that contains 17.4 ppm of K₂SO₄ (174 gmol^-1)? 
a) 2 x 10^-2 M
b) 2 x 10^-3 M
c) 4 x 10^-4 M
d) 2 x 10^-4 M
Answer: d

Question: Assuming that sea water is a 3.50 weight per cent aqueous solution of NaCl. What is the molality of sea water ?
a) 0.062 m
b) 0.0062 m 
c) 0.62 m
d) 6.2 m
Answer: c

Question: If the osmotic pressure of a 0.010 M aqueous solution of sucrose at 27° Cis 0.25 atm, then the osmotic pressure of a 0.010 M aqueous solution of NaCl at 27° C is
a) 0.062 atm
b) 0.12 atm
c) 0.25 atm
d) 0.50 atm
Answer: d

Question: A solution of 1.25 g of P in 50 g of water lower freezing point by 0.3° C Molar mass of P is 94,
K_f (water)= 1.86 K kg mol^-1 . The degree of association of P in water is 
a) 80%
b) 60%
c) 65%
d) 75%
Answer: a

Question: 5 L of a solution contains 25 mg of CaCO₃ . What is its concentration in ppm? (mol. wt. of CaCO₃ is 100)
a) 25
b) 1
c) 5
d) 2500
Answer: c

Question: Two solutions of a substance (non-electrolyte) are mixed in the following manner. 480 mL of 1.5 M (first solution) + 520mL of 1.2 M second solution. What is the molarity of the final mixture ?
a) 2.70 M
b) 1.344 M
c) 1.50 M
d) 1.20 M
Answer: b

Question: Molarity of 0.2 N H₂SO₄ is
a) 0.2
b) 0.4
c) 0.6
d) 0.1
Answer: d

Question: Glucose is mixed in 1 litre water, the ratio of ΔT_f / K_f changed to 10^-3 . The mass of glucose (C₆H₁₂O₆ ) is
a) 180 gram
b) 18 gram 
c) 1.8 gram
d) 0.18 gram
Answer: d

Question: Which among the following is a non-colligative property
a) elevation in boiling point 
b) osmotic pressure
c) refractive index
d) lowering of vapour pressure
Answer: c

Question: The sum of mole fractions of A, B and C in an aqueous solution containing 0.2 moles of each A, B and C is
a) 0.6
b) 0.2
c) 1.0
d) 1.2
Answer: c

Question: 25 mL of 3.0 M HCl are mixed with 75 mL of 4.0 M HCl. If the volumes are additive, the molarity of the final mixture will be
a) 4.0 M
b) 3.75 M
c) 4.25 M
d) 3.50 M
Answer: b

Question: A mixture of ethane and ethene occupies 41 L at 1 atm and 500 K. The mixture reacts completely with 10/3 mole of O₂  to produce CO₂ and H₂O. The mole fraction of ethane and ethene in the mixture are
a) 0.50, 0.50
b) 0.75, 0.25
c) 0.67, 0.33
d) 0.25, 0.75
e) 0.33, 0.67
Answer: c

Question: In countries nearer to polar region, the roads are sprinkled with CaCl₂. This is
a) To minimise the wear and tear of the roads
b) To minimise the snow fall
c) To minimise pollution
d) To minimise the accumulation of dust on the road
Answer: a