CBSE Class 9 Science Is Matter Around us Pure MCQs Set 06

Question: Which of the following is not an example of a physical change?
a) Dissolving sugar in water
b) Casting iron in moulds
c) Setting of cement
d) Magnetisation of iron
Answer: c

Question: The fine particles of an insoluble substance uniformly dispersed throughout a gas or liquid is called
a) suspension
b) precipitate
c) colloidal solution
d) impurity
Answer: c

Question: Separation of petroleum into its components is done by
a) chromatography
b) sublimation
c) distillation
d) fractional distillation
Answer: d

Question: Which gas present in air has the highest boiling point?
a) Oxygen
b) Nitrogen
c) Argon
d) Hydrogen
Answer: a

Question: Which of the following is a homogeneous mixture?
a) Solution of sugar in water
b) Chalk powder in water
c) Kerosene oil in water
d) None of these
Answer: a

Question: Identify the false statement.
a) Colloids are homogeneous
b) Colloids show Tyndall effect
c) Colloids show Brownian movement
d) The size of colloidal particles ranges between 1–100 nm
Answer: a

Question: Smoke is an example of
a) gas dispersed in liquid
b) gas dispersed in solid
c) solid dispersed in gas
d) solid dispersed in solid
Answer: c

Question: Brass contains
a) gold and copper
b) copper and zinc
c) zinc and silver
d) copper and silver
Answer: b

Question: Which of the following is not true for a compound?
a) A compound is heterogeneous in nature
b) A compound contains different elements in a fixed ratio
c) Properties of a compound are entirely different from those of the elements present in it
d) Constituents of a compound cannot be separated by simple physical methods
Answer: a

Question: Select the odd one out.
a) Carbon
b) Oxygen
c) Iodine
d) Mercury
Answer: d

Question: An example of a chemical change is
a) formation of clouds
b) glowing of an electric light
c) dropping sodium into water
d) dissolving of salt in water
Answer: c

Question: We can separate a pure solid from its solution by
a) crystallization
b) simple distillation
c) sedimentation
d) both (a) and (b)
Answer: a

Question: Identify the correct statement(s).
a) Mixtures which have a uniform composition throughout are called homogeneous mixtures or solutions
b) A homogeneous mixture can have a variable composition
c) Heterogeneous mixtures have non-uniform compositions
d) All of these
Answer: d

Question: If we heat iodine, then it is a
a) physical change
b) chemical change
c) no change
d) colour change
Answer: a

Question: The process by which one component is soluble in a solvent and separated by crystallization is
a) A mixture in which one component is soluble in a solvent
b) A mixture in which impurities are soluble in a solvent
c) A mixture in which both components are soluble in a solvent
d) A mixture in which both components are insoluble in water
Answer: a

Question: If the components of a substance can be separated only by a chemical change, then it is a
a) element
b) compound
c) mixture
d) both (a) and (b)
Answer: b

Question: Chemical changes are
a) temporary, reversible and a new substance is produced
b) always accompanied by exchange of light
c) permanent, irreversible and a new substance is produced
d) never accompanied by exchange of light and heat energy
Answer: c

Question: A student mixed iron filings and sulphur powder in a dish. Which liquid will you suggest to separate them?
a) Carbon disulphide
b) Cold water
c) Boiling water
d) Kerosene
Answer: a

Question: Which one of the following is correctly matched?
a) Emulsion – curd
b) Foam – mist
c) Aerosol – smoke
d) Solid sol – cake
Answer: c

Question: Soda water is a solution of carbon dioxide in water. What is this solution composed of?
a) Liquid solute in a gaseous solvent
b) Gaseous solute in a liquid solvent
c) Liquid solute in a liquid solvent
d) Gas in suspended form in liquid
Answer: b

Question: Select the incorrect statements(s).
1. Although ice, water and water vapour all look different and display different physical properties, they are chemically the same.
2. During burning of a candle, both physical and chemical changes take place.
3. Both water and cooking oil are liquid but their chemical characteristics are different. They differ in odour and inflammability.
4. It is the physical property of oil that makes it different from water.
(a) 1 and 2
(b) 2 and 3
(c) 1, 2 and 3
(d) Only 4
Answer: d

Question: Which of the following are metalloid?
1. Boron
2. Sodium
3. Silicon
4. Chlorine
5. Germanium
(a) 2 and 4
(b) 1 and 4
(c) 3 and 5
(d) 1, 3 and 5
Answer: d

FILL IN THE BLANK

Question: Matter is made up of small ………..
Answer: particles

Question: Latent heat of fusion is the amount of heat energy required to change 1 kg of solid into liquid at its ……….
Answer: melting point

Question: Forces of attraction in liquids are than in solids.
Answer: weaker

Question: As the volume of a specific amount of gas decreases, it’s pressure ……….
Answer: increases

Question: Usually the total charge of a plasma is ……….
Answer:  zero

Question: The pressure inside a sealed tube, if you raise the temperature go ……….
Answer: up

Question: As the temperature of a gas decreases, its volume ………
Answer: decreases

Question: Rapid evaporation depends on the area exposed to atmosphere.
Answer: surface

TRUE/FALSE

Question: The rate of evaporation depends only on the surface area exposed to the atmosphere
Answer: False

Question: Because electrons have been stripped away from atoms in plasma, plasmas have a negative charge.
Answer: False

Question: Gases present in air have the same pressure throughout the entire atmosphere.
Answer: False

Question: The molecules in a gas are in constant motion.
Answer: True

Question: Atoms in a liquid are farther apart than the atoms in a gas.
Answer: False

Question: It is just as easy to compress a liquid, as it is to compress a gas.
Answer: False

Question: Evaporation is a surface phenomenon.
Answer: True

Question: Evaporation and boiling are the same processes because molecules move from a liquid to gaseous state.
Answer: False

ASSERTION AND REASON

Question: Assertion : A mixture of benzoic acid and naphthalene can be separated by crystallization from water.
Reason : Benzoic acid is soluble in hot water but naphthalene is insoluble in hot water.
Options:
(a) Both assertion (A) and reason (R) are true and reason (R) is the correct explanation of assertion (A).
(b) Both assertion (A) and reason (R) are true but reason (R) is not the correct explanation of assertion (A).
(c) Assertion (A) is true but reason (R) is false.
(d) Assertion (A) is false but reason (R) is true.
Answer: a

Question: Assertion : Tyndall effect is an optical property.
Reason : Electrophoresis is an electrical property.
Options:
(a) Both assertion (A) and reason (R) are true and reason (R) is the correct explanation of assertion (A).
(b) Both assertion (A) and reason (R) are true but reason (R) is not the correct explanation of assertion (A).
(c) Assertion (A) is true but reason (R) is false.
(d) Assertion (A) is false but reason (R) is true.
Answer: b

Question: Assertion : In sublimation, a substance changes directly from solid to vapour without passing through liquid state and vice-versa.
Reason : Distillation involves two processes i.e., vaporisation and condensation.
Options:
(a) Both assertion (A) and reason (R) are true and reason (R) is the correct explanation of assertion (A).
(b) Both assertion (A) and reason (R) are true but reason (R) is not the correct explanation of assertion (A).
(c) Assertion (A) is true but reason (R) is false.
(d) Assertion (A) is false but reason (R) is true.
Answer: b

Question: Assertion : Hot water is used for separation of benzoic acid from naphthalene.
Reason : Whenever a crystal is formed it tends to leave out the impurities.
Options:
(a) Both assertion (A) and reason (R) are true and reason (R) is the correct explanation of assertion (A).
(b) Both assertion (A) and reason (R) are true but reason (R) is not the correct explanation of assertion (A).
(c) Assertion (A) is true but reason (R) is false.
(d) Assertion (A) is false but reason (R) is true.
Answer: b

Question: Assertion : A mixture of camphor and ammonium chloride cannot be separated by sublimation.
Reason : Camphor on heating sublimes, ammonium chloride does not.
Options:
(a) Both assertion (A) and reason (R) are true and reason (R) is the correct explanation of assertion (A).
(b) Both assertion (A) and reason (R) are true but reason (R) is not the correct explanation of assertion (A).
(c) Assertion (A) is true but reason (R) is false.
(d) Assertion (A) is false but reason (R) is true.
Answer: c

Question: Assertion : A solution of table salt in a glass of water is homogeneous.
Reason : A solution having different composition throughout is homogeneous.
Options:
(a) Both assertion (A) and reason (R) are true and reason (R) is the correct explanation of assertion (A).
(b) Both assertion (A) and reason (R) are true but reason (R) is not the correct explanation of assertion (A).
(c) Assertion (A) is true but reason (R) is false.
(d) Assertion (A) is false but reason (R) is true.
Answer: c

Question: Assertion : A mixture of glucose and m -dinitrobenzene can be separated by shaking it with ether.
Reason : Glucose is soluble in water.
Options:
(a) Both assertion (A) and reason (R) are true and reason (R) is the correct explanation of assertion (A).
(b) Both assertion (A) and reason (R) are true but reason (R) is not the correct explanation of assertion (A).
(c) Assertion (A) is true but reason (R) is false.
(d) Assertion (A) is false but reason (R) is true.
Answer: b

Question: Assertion : A mixture of acetone and methanol can be separated by fractional distillation.
Reason : The difference between their boiling points is very less.
Options:
(a) Both assertion (A) and reason (R) are true and reason (R) is the correct explanation of assertion (A).
(b) Both assertion (A) and reason (R) are true but reason (R) is not the correct explanation of assertion (A).
(c) Assertion (A) is true but reason (R) is false.
(d) Assertion (A) is false but reason (R) is true.
Answer: a