CBSE Class 9 Science Matter In Our Surroundings MCQs Set D

Question: Which of the following pair of gases cannot be separated by diffusion method?
a) SO₂ and H₂
b) CO₂ and N₂O
c) NH₃ and N₂
d) CO₂ and H₂
Answer: b

Question: The evaporation of a liquid can be best carried out in a
a) beaker
b) China dish
c) test tube
d) flask
Answer: b

Question: Kinetic energy of molecules is directly proportional to
a) temperature
b) pressure
c) both (a) and (b)
d) atmospheric pressure
Answer: a

Question: Ice floats on the surface of water because:
a) it is heavier than water
b) the density of both water and ice is the same
c) ice is lighter than water
d) none of these
Answer: c

Question: Evaporation of a liquid can take place
a) at its boiling point
b) below its boiling point
c) above its boiling point
d) at fixed temperature
Answer: b

Question: The forces of attraction between the particles of matter is maximum in
a) iron rod
b) kerosene oil
c) glycerine
d) dry air
Answer: a

Question: Which of the following states has the least energetic molecules?
a) Solids
b) Liquids
c) Gases
d) Plasmas
Answer: a

Question: To separate the solids which are insoluble in liquids such that solid is heavier than liquid:
a) sedimentation and decantation
b) evaporation and condensation
c) filtration
d) condensation and crystallization
Answer: a

Question: In an experiment oxygen was added to hydrogen and heated. On burning a substance containing both oxygen and hydrogen water was formed. What is this substance?
a) Element
b) Compound
c) Solution
d) Mixture
Answer: b

Question: A saturated salt water solution was heated and allowed to cool without adding any more salt. What will happen?
a) Some salt appears to settle at the bottom.
b) Some more salt can be dissolved now.
c) No change takes place.
d) Both (a) and (b)
Answer: c

Question: Addition of impurities to water:
a) decreases the freezing point of water
b) increases the boiling point of water
c) does not affect the freezing or boiling point of water
d) both (a) and (b)
Answer: d

Question: A gas can be best liquefied
a) by increasing the temperature
b) by lowering the pressure
c) by increasing the pressure and reducing the temperature
d) none of these
Answer: c

Question: The electric bulb on long use forms a black coating on its inner surface. The process associated with this is
a) melting of tungsten
b) sublimation of tungsten
c) oxidation of tungsten
d) reduction of tungsten
Answer: b

Question: If a few spoons of salt are dissolved in pure water then
a) its boiling point becomes less than 100°C
b) its boiling point becomes more than 100°C
c) its freezing point becomes more than 0°C
d) none of these
Answer: b

Question: When liquid starts boiling, further heat energy which is supplied
a) is lost to the surroundings as much
b) increases the temperature of the liquid
c) increases the kinetic energy of the particles in the liquid
d) is absorbed as latent heat of vaporisation by the liquid
Answer: d

Question: You can separate a mixture of sand, salt and water by:
a) filtration and distillation
b) decantation and evaporation
c) filtration and decantation
d) decantation and crystallization
Answer: b

Question: Which of the following is not correct regarding gases?
a) Gases exert pressure.
b) Gases have large intermolecular spaces.
c) Gases have weak tendency to diffuse.
d) Gases have weak intermolecular forces of attraction.
Answer: c

Question: In which form do the water molecules have less kinetic energy?
a) Ice
b) Water
c) Steam
d) All of them have equal kinetic energy
Answer: a

Question: The state of matter which consists of super energetic particles in the form of ionized gases is called
a) gaseous state
b) liquid state
c) Bose-Einstein condensate
d) plasma state
Answer: d

Question: Which of the following describes the liquid phase?
a) It has a definite shape and a definite volume.
b) It has a definite shape but not definite volume.
c) It has a definite volume but not a definite shape.
d) It has neither a definite shape nor a definite volume.
Answer: c

Question: Which of the following statements is not correct?
a) Matter is continuous in nature.
b) Inter-particle spaces are maximum in the gaseous state of a substance.
c) Particles which constitute the matter follow a zigzag path.
d) Solid state is the most compact state of a substance.
Answer: c

Question: Sugar syrup, usually used to coat sweets with sugar, becomes hard when cooled. From this we can conclude that sugar syrup is:
a) a saturated solution
b) an unsaturated solution
c) not a solution
d) none of these
Answer: a

Question: Alcohol exists as a liquid at room temperature because
a) the intermolecular forces are strong enough to keep its particles bound to each other
b) its melting point is below room temperature
c) it is highly compressible
d) both (a) and (b)
Answer: d

Question: The quantity of matter present in an object is called its
a) weight
b) gram
c) mass
d) density
Answer: c

Question: Which of the following process(es) release(s) heat?
1. Condensation
2. Vaporisation
3. Freezing
4. Melting
(a) Only 1
(b) Only 4
(c) 1 and 3
(d) 2 and 4
Answer: c

Question: Evaporation is directly proportional to
1. humidity
2. surface area
3. temperature
4. wind speed
(a) 1 and 4
(b) 2 and 3
(c) 3 and 4
(d) 2, 3 and 4
Answer: d

Question: Which of the following statements about evaporation is incorrect?
1. It is bulk phenomena.
2. It is a fast process.
3. It takes place at all temperatures.
(a) 2 and 3
(b) 1 and 2
(c) 1 and 3
(d) 1, 2 and 3
Answer: b

FILL IN THE BLANK

Question: Compounds are formed by chemically combining elements in a proportion by weight.
Answer: definite

Question: can be classified chemically into pure substance and mixtures.
Answer: Matter

Question: Soda water can be separated by the pressure.
Answer: lowering

Question: During distillation of iodine and methyl alcohol the non-volatile substance is ……….
Answer: iodine

Question: A mixture of barium sulphate and H2O can be separated by the method of ……….
Answer: filtration

Question: The principle of difference in boiling points of liquid is used in the ……….
Answer: fractional distillation

Question: During the separation of CO2 and O2 by the process of preferential liquefaction, the component ………. liquefies.
Answer: cO2

Question: Both elements and compounds are substances.
Answer: pure

TRUE/FALSE

Question: Distilled water cannot be separated into its constituents by physical methods.
Answer: True

Question: Sand and sawdust can be separated by gravity method.
Answer: True

Question: The properties of compounds are same from those of the elements of which they are made.
Answer: False

Question: A handful of soil is homogeneous mixture of solids.
Answer: False

Question: Separation of CCl4 from CS2 can be carried out by separating funnel method.
Answer: False

ASSERTION AND REASON

Question: Assertion : Camphor disappears without leaving any residue.
Reason : Camphor undergoes sublimation.
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 : Solids do not diffuse in air.
Reason : The particles are closely packed in solids.
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 : The conversion of a gas directly into solid is called condensation.
Reason : Naphthalene leaves residue when kept open for some time.
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.

Question: Assertion : The rate of evaporation increases with increase in temperature.
Reason : Increase in temperature increases the kinetic energy of the particles.
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 : The intermolecular forces in solid state are stronger than those in the liquid state.
Reason : The space between the particles of matter is called intermolecular space.
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 gas can be easily compressed by applying pressure.
Reason : Since the inter-particle spaces in the gaseous state are very small, they cannot be decreased by applying pressure.
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 : Ice floats on the surface of water.
Reason : The density of both water and ice is same.
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 : Liquids diffuse less easily as compared to gases.
Reason : Intermolecular forces are greater in gases.
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 : At normal pressure (1 atm) the boiling point of water is 100cC or 373.15 K.
Reason : As the pressure increases, boiling point of water also increases.
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 : During evaporation of liquids, the temperature remains unaffected.
Reason : Kinetic energy of the molecules is inversely proportional to absolute temperature.
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: d