Important MCQs on mixtures-solutions-and-their-separation-techniques-for-CBSE Class-9-Science-Chapter-2
Understanding these separation techniques helps in effectively separating and purifying mixtures in both everyday life and scientific applications:
Here are 50 more multiple-choice-questions-related-to-mixtures-solutions-and-their-separation-techniques
51. Which of the following methods would
be best for separating a mixture of sand and salt if you have access to a
magnet?
A) Filtration
B) Evaporation
C) Magnetic separation
D) Centrifugation
Answer: C) Magnetic separation
Explanation: Magnetic separation can
be used if one of the components (e.g., iron filings) is magnetic, but for sand
and salt, it's not applicable as both are non-magnetic.
52. What technique separates substances based on their boiling points?
A) Filtration
B) Distillation
C) Chromatography
D) Centrifugation
Answer: B) Distillation
Explanation: Distillation separates
substances based on their different boiling points.
53. What type of mixture is milk
classified as?
A) Solution
B) Colloid
C) Suspension
D) Emulsion
Answer: B) Colloid
Explanation: Milk is a colloid because
it contains fat droplets dispersed in water.
54. Which separation technique would you
use to obtain a pure solvent from a solution?
A) Filtration
B) Distillation
C) Centrifugation
D) Chromatography
Answer: B) Distillation
Explanation: Distillation is used to
separate a pure solvent from a solution by utilizing the different boiling
points of the components.
55. In which type of mixture are the
particles too small to be seen with the naked eye?
A) Suspension
B) Colloid
C) Solution
D) Emulsion
Answer: C) Solution
Explanation: In solutions, the
particles are at the molecular or ionic level and are not visible to the naked
eye.
56. Which of the following is not a method
for separating mixtures?
A) Filtration
B) Distillation
C) Evaporation
D) Conduction
Answer: D) Conduction
Explanation: Conduction is not a
separation method; it refers to heat transfer through materials.
57. How would you separate a mixture of
sand and iron filings?
A) Filtration
B) Magnetism
C) Distillation
D) Chromatography
Answer: B) Magnetism
Explanation: Iron filings can be
separated from sand using a magnet, as iron is magnetic and sand is not.
58. Which method would be best for
separating different colours in a dye?
A) Filtration
B) Chromatography
C) Centrifugation
D) Evaporation
Answer: B) Chromatography
Explanation: Chromatography is ideal
for separating different pigments or colours based on their movement through a
medium.
59. What is the process of separating a
mixture by passing it through a porous material called?
A) Filtration
B) Distillation
C) Evaporation
D) Chromatography
Answer: A) Filtration
Explanation: Filtration separates
solids from liquids by passing the mixture through a filter.
60. Which method would you use to separate
a mixture of oil and water?
A) Filtration
B) Centrifugation
C) Separating funnel
D) Evaporation
Answer: C) Separating funnel
Explanation: A separating funnel is
used to separate immiscible liquids like oil and water based on their different
densities.
61. What type of mixture is gelatine?
A) Solution
B) Colloid
C) Suspension
D) Emulsion
Answer: B) Colloid
Explanation: Gelatine is a colloid
where a liquid is dispersed in a solid matrix.
62. What is the main principle behind
centrifugation?
A) Difference in boiling points
B) Difference in solubility
C) Difference in density
D) Difference in particle size
Answer: C) Difference in density
Explanation: Centrifugation separates
substances based on differences in their densities by spinning the mixture at
high speeds.
63. How would you separate a mixture of
sand and water?
A) Chromatography
B) Filtration
C) Distillation
D) Centrifugation
Answer: B) Filtration
Explanation: Filtration separates the
sand (solid) from the water (liquid) in a mixture.
64. What type of mixture is fog?
A) Solution
B) Colloid
C) Suspension
D) Emulsion
Answer: B) Colloid
Explanation: Fog is a colloid where
tiny water droplets are dispersed in air.
65. Which separation technique relies on
differences in solubility?
A) Filtration
B) Chromatography
C) Distillation
D) Centrifugation
Answer: B) Chromatography
Explanation: Chromatography separates
substances based on their different solubilities and affinities for the
stationary and mobile phases.
66. What type of mixture is orange juice
with pulp?
A) Solution
B) Colloid
C) Suspension
D) Emulsion
Answer: C) Suspension
Explanation: Orange juice with pulp is
a suspension because the pulp particles are suspended in the juice and can
settle out over time.
67. What is the process of removing a
solvent from a solution called?
A) Filtration
B) Distillation
C) Chromatography
D) Centrifugation
Answer: B) Distillation
Explanation: Distillation involves
boiling a solution to remove the solvent, leaving the solute behind.
68. Which of the following is not an
example of a colloid?
A) Milk
B) Gelatine
C) Orange juice
D) Foam
Answer: C) Orange juice
Explanation: Orange juice is typically
a suspension if it contains pulp, but it is not a colloid.
69. How can you obtain pure salt from
seawater?
A) Filtration
B) Chromatography
C) Distillation
D) Centrifugation
Answer: C) Distillation
Explanation: Distillation is used to
separate the water from the salt, leaving pure salt behind.
70. What is the main difference between a
solution and a colloid?
A) Particle size
B) Density
C) Solubility
D) Colour
Answer: A) Particle size
Explanation: Solutions have particles
at the molecular level, whereas colloids have larger particles that do not
settle out.
71. Which of the following would be best
for separating a mixture of liquids with different densities?
A) Filtration
B) Distillation
C) Separating funnel
D) Chromatography
Answer: C) Separating funnel
Explanation: A separating funnel is
used to separate immiscible liquids based on their different densities.
72. What process involves the heating of a
liquid to form vapor and then cooling the vapor to form a liquid?
A) Filtration
B) Distillation
C) Centrifugation
D) Chromatography
Answer: B) Distillation
Explanation: Distillation involves
heating a liquid to vaporize it and then cooling it to condense it back to a
liquid.
73. Which technique is used to separate
substances based on particle size?
A) Filtration
B) Distillation
C) Chromatography
D) Centrifugation
Answer: A) Filtration
Explanation: Filtration separates
substances based on particle size, where larger particles are trapped while
smaller ones pass through.
74. What type of mixture is smoke?
A) Solution
B) Colloid
C) Suspension
D) Emulsion
Answer: B) Colloid
Explanation: Smoke is a colloid where
solid particles are dispersed in a gas.
75. Which of the following mixtures would
you expect to see layers in?
A) Saltwater
B) Vinegar
C) Sand and water
D) Coffee
Answer: C) Sand and water
Explanation: Sand and water form
layers because sand is not dissolved and settles out, forming a distinct layer.
76. Which of the following methods would
you use to separate a mixture of salt and sand, where you want to keep both
components?
A) Filtration followed by evaporation
B) Distillation
C) Magnetic separation
D) Chromatography
Answer: A) Filtration followed by
evaporation
Explanation: Filtration separates sand
from saltwater, and then evaporation removes the water to obtain the salt.
77. What is the main principle behind the
process of evaporation?
A) Difference in solubility
B) Difference in boiling points
C) Difference in particle size
D) Difference in density
Answer: B) Difference in boiling
points
Explanation: Evaporation relies on the
difference in boiling points, where the solvent evaporates leaving the solute
behind.
78. What technique is used to purify
liquids based on differences in the rate of movement through a medium?
A) Filtration
B) Chromatography
C) Distillation
D) Centrifugation
Answer: B) Chromatography
Explanation: Chromatography separates
substances based on their movement through a medium at different rates.
79. Which of the following is an example
of a homogeneous mixture?
A) Salad
B) Sand and salt
C) Air
D) Oil and water
Answer: C) Air
Explanation: Air is a homogeneous
mixture because its components are evenly distributed at the molecular level.
80. Which separation method is most
effective for separating a liquid from a solid that has been dissolved?
A) Filtration
B) Distillation
C) Chromatography
D) Centrifugation
Answer: B) Distillation
Explanation: Distillation separates a
liquid from dissolved solids based on differences in boiling points.
81. What is the process called where a
mixture is separated into its individual components based on different
affinities to a stationary and a mobile phase?
A) Filtration
B) Chromatography
C) Distillation
D) Evaporation
Answer: B) Chromatography
Explanation: Chromatography separates
components of a mixture based on their differing affinities for a stationary
phase and a mobile phase.
82. How would you separate a mixture of
oil and water without using a separating funnel?
A) Filtration
B) Evaporation
C) Centrifugation
D) Using a paper towel
Answer: C) Centrifugation
Explanation: Centrifugation can help
separate oil and water based on their different densities.
83. What type of mixture is blood
classified as?
A) Solution
B) Colloid
C) Suspension
D) Emulsion
Answer: C) Suspension
Explanation: Blood is a suspension
because it contains cells and other particles suspended in plasma.
84. Which of the following processes is
used to purify a liquid by removing dissolved solids?
A) Filtration
B) Evaporation
C) Distillation
D) Centrifugation
Answer: C) Distillation
Explanation: Distillation is used to
purify liquids by removing dissolved solids through evaporation and
condensation.
85. Which technique separates components
based on differences in their solubility in a solvent?
A) Filtration
B) Chromatography
C) Distillation
D) Centrifugation
Answer: B) Chromatography
Explanation: Chromatography separates
components based on their differing solubilities in a solvent.
86. What type of mixture is a fruit salad?
A) Solution
B) Colloid
C) Suspension
D) Emulsion
Answer: C) Suspension
Explanation: A fruit salad is a
suspension because the individual fruit pieces are suspended in the mix and are
distinct from one another.
87. Which method would be suitable for
separating a mixture of liquids with different boiling points?
A) Filtration
B) Chromatography
C) Distillation
D) Centrifugation
Answer: C) Distillation
Explanation: Distillation separates
liquids based on their different boiling points.
88. What is the main purpose of using a
centrifuge?
A) To heat mixtures
B) To separate liquids from solids
based on density
C) To dissolve substances
D) To filter liquids
Answer: B) To separate liquids from
solids based on density
Explanation: A centrifuge separates
components based on their density by spinning the mixture rapidly.
89. Which of the following is an example
of a physical method of separation?
A) Chemical reaction
B) Filtration
C) Dissolution
D) Neutralization
Answer: B) Filtration
Explanation: Filtration is a physical
method used to separate solids from liquids or gases.
90. What kind of mixture is mayonnaise?
A) Solution
B) Colloid
C) Suspension
D) Emulsion
Answer: D) Emulsion
Explanation: Mayonnaise is an
emulsion, a type of mixture where fat droplets are dispersed in water.
91. Which technique would you use to
separate different components of a mixture based on their different rates of
movement through a stationary phase?
A) Filtration
B) Distillation
C) Chromatography
D) Centrifugation
Answer: C) Chromatography
Explanation: Chromatography separates
components based on their different rates of movement through a stationary
phase.
92. What separation technique is used to
separate a mixture of solids with different particle sizes?
A) Filtration
B) Distillation
C) Sifting
D) Centrifugation
Answer: C) Sifting
Explanation: Sifting separates solids
based on particle size, where larger particles are retained and smaller ones
pass through.
93. What method would you use to separate
a soluble solid from a liquid?
A) Filtration
B) Evaporation
C) Chromatography
D) Centrifugation
Answer: B) Evaporation
Explanation: Evaporation is used to
remove the liquid, leaving behind the soluble solid.
94. How would you separate a mixture of
sand and water to obtain the sand?
A) Distillation
B) Filtration
C) Chromatography
D) Evaporation
Answer: B) Filtration
Explanation: Filtration will separate
the sand (solid) from the water (liquid).
95. What is the primary principle behind
using a separating funnel for mixture separation?
A) Difference in solubility
B) Difference in density
C) Difference in particle size
D) Difference in boiling points
Answer: B) Difference in density
Explanation: A separating funnel
separates liquids based on their different densities.
96. What kind of mixture is sand in water?
A) Solution
B) Colloid
C) Suspension
D) Emulsion
Answer: C) Suspension
Explanation: Sand in water forms a
suspension because the sand particles are suspended in the water and can settle
over time.
97. Which separation method is best suited
for separating a mixture of two immiscible liquids?
A) Filtration
B) Chromatography
C) Centrifugation
D) Separating funnel
Answer: D) Separating funnel
Explanation: A separating funnel is
used for separating immiscible liquids based on their different densities.
98. What type of mixture is whipped cream?
A) Solution
B) Colloid
C) Suspension
D) Emulsion
Answer: B) Colloid
Explanation: Whipped cream is a
colloid where air is dispersed in a liquid cream.
99. Which method would you use to separate
sugar from a sugar solution?
A) Filtration
B) Distillation
C) Chromatography
D) Evaporation
Answer: D) Evaporation
Explanation: Evaporation removes the
water from the sugar solution, leaving sugar behind.
100. Which of the following is the most
effective way to separate a mixture of salt and water?
A) Filtration
B) Distillation
C) Sifting
D) Chromatography
Answer: B) Distillation
Explanation: Distillation is effective
in separating salt from water by boiling and condensing the vapor.
Conclusion
Understanding
the separation techniques and properties of mixtures is essential for various
scientific and practical applications. Each method—whether it’s filtration,
distillation, chromatography, centrifugation, or using a separating funnel—has
specific principles and is suited for particular types of mixtures. For
instance, distillation is ideal for separating liquids based on boiling points,
while chromatography excels in separating components based on solubility and
movement through a medium. Filtration is useful for separating solids from
liquids, and centrifugation relies on density differences to separate
components.
In everyday
life and scientific work, choosing the correct method depends on the nature of
the mixture and the desired outcome. For example, to purify seawater,
distillation is employed to separate salt from water. Conversely, to separate a
mixture of sand and iron filings, a magnet is used to attract the iron. The
principles of these techniques—ranging from differences in solubility and
density to particle size and boiling points—highlight the diverse approaches
needed to handle various separation challenges effectively.
By mastering these techniques, students can apply their knowledge to practical scenarios and understand the fundamental concepts behind the purification and separation of mixtures in both academic and real-world contexts.