CBSE Class 9 Science Matter In Our Surroundings MCQs Set A

Question: When a gas jar full of air is placed upside down on a gas jar full of bromine vapours, the red-brown vapours of bromine from the lower jar go upward into the jar containing air. In this experiment:
(a) Air is heavier than bromine
(b) Both air and bromine have the same density
(c) Bromine is heavier than air
(d) Bromine cannot be heavier than air because it is going upwards against gravity 

Answer:   C

Question: When water at 0°C freezes to form ice at the same temperature of 0°C, then it:
(a) Absorbs some heat
(b) Releases some heat
(c) Neither absorbs nor releases heat
(d) Absorbs exactly 3.34 x 105J/kg of heat

Answer:   B

Question: The evaporation of a liquid can best be carried out in a:
(a) Flask
(b) China dish
(c) T est tube
(d) Beaker

Answer:   B

Question: Zig-zag movement of the solute particle in a solution is known as
(a) Linear motion
(b) Circular motion
(c) Brownian motion
(d) Curved motion.

Answer:   C

Question: CO₂ can be easily liquified and even solidified because
(a) It has weak forces of attraction
(b) It has comparatively more force of attraction than other gases
(c) It has more intermolecular space
(d) It is present in atmosphere.

Answer:   B

Question: A few substances are arranged in the increasing order of ‘forces of attraction’ between their particles. Which one of the following represents a correct arrangement?
(a) Water, air, wind
(b) Air, sugar, oil
(c) Oxygen, water, sugar
(d) Salt, juice, air

Answer:   C 

Question: Which of the following phenomena always results in the cooling effect?
(a) Condensation
(b) Evaporation
(c) Sublimation
(d) None of these

Answer:   B

Question: The colour of vapours formed on sublimation of iodine solid is
(a) Purple (violet)
(b) Colourless
(c) Yellow
(d) Orange

Answer:   A

Question: A gas which obeys the gas laws is known as:
(a) An ideal gas
(b) A heavier gas
(c) A lighter gas
(d) A real gas

Answer:   A

Question: What s the term used to describe the phase change as a liquid becomes a solid?
(a) Evaporation
(b) Condensation
(c) Freezing
(d) None of the above

Answer:   C

Question: Which of the following phenomena would increase on raising the temperature?
(a) Diffusion, evaporation, compression of gases
(b) Evaporation, compression of gases, solubility
(c) Evaporation, diffusion, expansion of gases
(d) Evaporation, solubility, diffusion, compression of gases

Answer:   C

Question: The quantity of matter present in an object is called its:
(a) Weight
(b) Gram
(c) Mass
(d) Density

Answer:   C

Question : As solid melts to form liquid:
(a) Inter particle distance increases 
(b) Inter molecular forces of attraction decreases
(c) Compressibility increases
(d) All of the above

Answer : D

Question : Which of the following is not characteristic of solid:
(a) High Rigidity 
(b) Regular Shape 
(c) High density 
(d) High compressibility

Answer : D

Question : The boiling point of water is:
(a) 101°C at atmospheric pressure
(b) 273K at atmospheric pressure
(c) 0°C at atmospheric pressure 
(d) 0K at atmospheric pressure

Answer : A

Question : Which of the following has highest intermolecular forces of attraction?
(a) Water at room temperature
(b) CO₂ gas
(c) Ethyl alcohol
(d) Iron metal

Answer : D

Question : Which of the following substances will undergo sublimation?
(a) Common salt
(b) Odonil
(c) Sugar
(d) Sand

Answer : B

Question : The process of evaporation causes:
(a) Cooling 
(b) Heating
(c) Dryness 
(d) None of the above

Answer : A

Question : The conversion of solid to gas directly is called:
(a) Evaporation 
(b) Sublimation
(c) Distillation
(d) condensation

Answer : B

Question : Evaporation of a liquid can take place:
(a) At its boiling point
(b) At all temperatures
(c) At its freezing point
(d) At a fixed temperature

Answer : B

Question : Which of the following describes a liquid state:
(a) Definite volume and definite shape
(b) Definite volume and no specific shape
(c) definite shape but no definite volume
(d) neither definite shape nor definite volume

Answer : B

Question : Wet clothes are kept for drying. Which of the following does not help them in drying:
(a) Spreading it out 
(b) Blowing wind over it 
(c) Making the room a little warmer 
(d) Cooling the room

Answer : D

Question : At higher altitudes the boiling points of liquids
(a) Increases
(b) Decreases
(c) Remains the same
(d) Increases then decreases

Answer : B

Question : During evaporation particles of a liquid change into vapours :
(a) From the surface 
(b) From the bulk 
(c) From the bottom 
(d) From all over the liquid

Answer : A

Question : In which phenomenon does water change into water vapour below its boiling point:
(a) Boiling 
(b) Evaporation 
(c) Freezing 
(d) Sublimation

Answer : B

Question : We get the smell of hot food in the kitchen outside the house because of:
(a) Boiling 
(b) Evaporation
(c) Sublimation 
(d) Diffusion

Answer : D