Matter In Our Surroundings(9th Grade > Chemistry ) Questions and answers for exam Preparation

9th Grade > Chemistry

MATTER IN OUR SURROUNDINGS MCQs

Total Questions : 54 | Page 5 of 6 pages

The amount of water vapour present in the air is known as _______.

Density
Humidity
Precipitation
Vapourisation

Discuss Question

Answer: Option B. -> Humidity
:
B
The air around us holds water in the form of vapour (gas). Humidity is the amount of water vapour present in the air. During winter, due to low temperature, the humidity in the air falls down. This is the reason why our skin becomes dry in winters.

Question 42.

Which of the following states of matter has the highest kinetic energy of the particles?

Solids
Liquids
Gases
All the states have same kinetic energy

Discuss Question

Answer: Option C. -> Gases
:
C
Higher the distance between the particles, lower is the inter particle force of attraction. Hence, particles would be free to move with higher kinetic energy.
Therefore, the order of kinetic energy: Solids < Liquids < Gases

Question 43.

Which of the following option correctly differentiates between evaporation and boiling of water?

Evaporation takes place only at $100^{\circ} C$ .
Evaporation takes place at a temperature below $100^{\circ} C$ .
Evaporation takes place only above $100^{\circ} C$ .
Both evaporation and boiling are same.

Discuss Question

Answer: Option B. -> Evaporation takes place at a temperature below

100^{\circ} C

.
:
B
Evaporation is the process by which a liquid is converted into vapour at any temperature below the boiling point of the liquid. It is a surface phenomenon. A common example of evaporation is drying of wet clothes.
Whereas, boiling is a bulk phenomenon occuring at a certain temperature called the boiling point. For example, water has a boiling point of

100^{\circ} C

Question 44.

The difference in various states of matter is due to the difference in the distances between their constituent particles.

True
False
Solids do not have a definite shape but have a definite volume.
Liquids have definite shape and volume.

Discuss Question

Answer: Option A. -> True
:
A

Matter is made up of particles. As the distances between the particles increases, the substance becomes less dense and physical state changes.
Solids, liquids, and gases are three major physical states of matter. Following is the order of distance between particles of different states of matter.
Gases > Liquids > Solids.

Question 45.

The level of water in a beaker rises when a spoon full of sugar is added to it.

True
False

Discuss Question

Answer: Option B. -> False
:
B
Materials that dissolve in water are soluble materials.
For example, when sugar is added to water, the sugar particles occupy the space between the water particles.
So there is no rise in the volume of water in the beaker.

Question 46.

A tightly closed container contains 500 ml of gas. Now, the gas is carefully transported into a 1000 ml container without any leakage. What is the volume of gas in the new container?

250 ml
500 ml
1000 ml
1500 ml

Discuss Question

Answer: Option C. -> 1000 ml
:
C
The volume of any gas is equal to the volume of the container in which it is present. This is because gases try to occupy the maximum space that is available. So, when a gas of 500 ml is transported into a container of 1000 ml, it occupies the entire space that is available i.e., 1000ml.

Question 47.

Assume a gas stored in a container at room temperature. Identify the physical effect(s) that is/are caused by the motion of the particles of gas inside the container.

Kinetic Energy
Pressure
Potential Energy
Temperature

Discuss Question

Answer: Option C. -> Potential Energy
:
A, B, and D
The particles of matter irrespective of any state are never at rest. The energy attained by the particles due to their motion is called its kinetic energy. This kinetic energy is responsible for the temperature of the gas. The pressure inside a gas (or liquid) container is due to the force that these particles exert on the walls of the container.
(Potential energy of a particle is due its position but not because of motion).

Question 48.

A sponge is compressible and hence, its not a solid.

True
False
1000 ml
1500 ml

Discuss Question

Answer: Option B. -> False
:
B
Sponge is a solid having tiny pores in it, which traps air. When we try to compress a sponge by applying pressure on it, the air trapped in these holes escape out. Hence, the sponge gets compressed.
However, when the applied pressure is removed, it comes back to its original shape. Hence, even though sponge is compressible, it is a solid.

Question 49.

With respect to the given assertion and reason. Choose the correct option.
Assertion [A]: With an increase in the temperature of a gas inside a container, its pressure also increases.
Reason [R]: Upon heating, the kinetic energy of the gas molecules increases, which in turn results in a greater force exerted on the walls of the container.

Both [A] and [R] are true and [R] is the correct explanation of [A]
Both [A] and [R] are true, but [R] is not the correct explanation for [A]
[A] is correct and [R] is incorrect
[A] is incorrect and [R] is correct

Discuss Question

Answer: Option A. -> Both [A] and [R] are true and [R] is the correct explanation of [A]
:
A

The pressure inside a container is due to the fact that the gas molecules which are always in motion hit and exert the force on the walls of the container. When the temperature is increased, the vibrational kinetic energy of molecules increases. This increases the pressure inside the container and the force exerted by the particles on the walls of the container.

Question 50.

What is the boiling point of water on Kelvin scale?