CBSE Class 12 Chemistry Solutions MCQs Set 05

Question: Which type of solution is petrol ?
(a) solid-liquid
(b) liquid-liquid
(c) gas-liquid
(d) all of these

Answer : B

Question: On increasing temperature the value of Henry's constant
(a) Decreases
(b) Increases
(c) Remains constant
(d) Uncertain

Answer : B

Question: Which solution has the highest effect of temperature on its vapour pressure ?
(a) Sugar solution
(b) NaCl solution
(c) BaCl₂ Solution
(d) Aqueous H₂S

Answer : D

Question: What is the value of van't Hoff factor when acetic acid is dissolved in benzene ?
(a) Zero
(b) 1
(c) >1
(d) <1

Answer : D

Question: The total pressure for volatile components A and B is 0.02 bar at equilibrium. If the mole fractions of component A is 0.2, then what will be partial pressure of component B ?
(a) 0.02 bar
(b) 0.04 bar
(c) 0.016 bar
(d) 0.2 bar

Answer : C

Question: Which unit of concentration value is changed with change in temperature ?
(a) Normality
(b) Molarity
(c) % V/V
(d) all of these

Answer : D

Question: On increasing temperature, the solubility of gaseous solute in liquid solvent
(a) Increases
(b) Decreases
(c) Remains constant
(d) Uncertain

Answer : B

Question: For which solution the value of van't Hoff factor is not 1 ?
(a) Glucose
(b) Sugar
(c) Fructose
(d) Acetic acid

Answer : D

Question: What is the value of van't Hoff factor for dilute FeCl₃ (aqueous) solution ?
(a) 1
(b) <1
(c) >1
(d) zero

Answer : C

Question: 0.05 M glucose solution is iso-osmotic with which of the following solution ?
(a) 0.10 M NaCl
(b) 0.05 NaCl
(c) 0.025 M NaCl
(d) 1 M NaCl

Answer : C

Question: What is the molality for 10% W/W NaOH(aq) solution ?
(a) 2.778
(b) 2.5
(c) 10
(d) 5

Answer : A

Question: Under which of the following conditions, will a solid dissolve in water ?
(a) Lattice energy > Hydration energy
(b) Lattice energy < Hydration energy
(c) Lattice energy = Hydration energy
(d) When dissolution is exothermic.

Answer : B

Question: Most of the processes in our body occur in
(a) solid solution
(b) liquid solution
(c) gaseous solution
(d) colloidal solution

Answer : B

Question: The mole fraction of water in a sulphuric acid solution is 0.85. Calculate the molality of the solution.
(a) 8.5 m
(b) 9.8 m
(c) 4.5 m
(d) 0.1 m

Answer : B

Question: The boiling point of an azeotropic mixture of water and ethanol is less than that of water and ethanol. The mixture shows
(a) no deviation from Raoult’s Law.
(b) positive deviation from Raoult’s Law.
(c) negative deviation from Raoult’s Law.
(d) that the solution is unsaturated.

Answer : B

Question: Partial pressure of a solution component is directly proportional to its mole fraction. This is known as
(a) Henry’s law
(b) Raoult’s law
(c) Distribution law
(d) Ostawald’s dilution law

Answer : B

Question: The volume of water that must be added to 40 mL of 0.25M oxalic acid solution to make it exactly decimal is:
(a) 100 mL
(b) 30 mL
(c) 60 mL
(d) 25 mL

Answer : C

Question: 3 moles of P and 2 moles of Q are mixed, what will be their total vapour pressure in the solution if their partial vapour pressures are 80 and 60 torr respectively?
(a) 80 torr
(b) 140 torr
(c) 72 torr
(d) 70 torr

Answer : C

Question: When a solute is present in trace quantities the following expression is used
(a) Gram per million
(b) Milligram percent
(c) Microgram percent
(d) Parts per million

Answer : D

Question: Which of the following solutions shows positive deviation from Raoult’s law?
(a) Acetone + Aniline
(b) Acetone + Ethanol
(c) Water + Nitric acid
(d) Chloroform + Benzene

Answer : B

Question: The system that forms maximum boiling azetrope is
(a) Acetone-chloroform
(b) ethanol-acetone
(c) n-hexane-n-heptane
(d) carbon disulphide-acetone

Answer : A

Question: The osmotic pressure of a solution can be increased by
(a) increasing the volume
(b) increasing the number of solute molecules
(c) decreasing the temperature
(d) removing semipermeable membrane

Answer : B

Question: For carrying reverse osmosis for desalination of water the material used for making semipermeable membrane is
(a) potassium nitrate
(b) parchment membrane
(c) cellulose acetate
(d) cell membrane

Answer : C

Question: What will be the degree of dissociation of 0.1 M Mg(NO₃)₂ solution if van’t Hoff factor is 2.74?
(a) 75%
(b) 87%
(c) 100%
(d) 92%

Answer : B

Question: If 2 gm of NaOH is present is 200 ml of its solution, its molarity will be
(a) 0.25
(b) 0.5
(c) 5
(d) 10

Answer : A

Question: Which of the following mixture is(are) called solution?
(i) water + ammonia (ii) water + acetone
(iii) acetone + alcohol (iv) hexane + water
(a) (i), (ii) and (iii) (b) (i), (iii) and (iv)
(c) (i) and (iv) (d) (ii) and (iii)

Answer : A