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# Test: Effect Of Heat And Pressure On Matter

## 15 Questions MCQ Test Science Class 9 | Test: Effect Of Heat And Pressure On Matter

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This mock test of Test: Effect Of Heat And Pressure On Matter for Class 9 helps you for every Class 9 entrance exam. This contains 15 Multiple Choice Questions for Class 9 Test: Effect Of Heat And Pressure On Matter (mcq) to study with solutions a complete question bank. The solved questions answers in this Test: Effect Of Heat And Pressure On Matter quiz give you a good mix of easy questions and tough questions. Class 9 students definitely take this Test: Effect Of Heat And Pressure On Matter exercise for a better result in the exam. You can find other Test: Effect Of Heat And Pressure On Matter extra questions, long questions & short questions for Class 9 on EduRev as well by searching above.
QUESTION: 1

### Particles of matter are continuously moving. What is the effect of rise in temperature on moving particles?

Solution:

Rise in temperature gives the particles some energy to move faster.

QUESTION: 2

### Latent heat of fusion is the amount of heat energy required to change:

Solution:

Latent heat of fusion is the amount of heat energy required to change 1 kg of solid into liquid state without any change in temperature, at its melting point.

QUESTION: 3

### The hardness of solids is due to the fact that their particles:

Solution:

Liquids will flow and fill up any shape of container. Solids like to hold their shape. In the same way that a large solid holds its shape, the atoms inside of a solid are not allowed to move around too much. Atoms and molecules in liquids and gases are bouncing and floating around, free to move where they want.

QUESTION: 4

CO2 can be easily liquified and even solidified because

Solution:

COcan be easily liquefied and even solidified because the inter molecular force of attraction between the particles of carbon dioxide is very much less this means that when you're cool down the gas or reduce the pressure by a small extend the molecules become less excited and become solid.

QUESTION: 5

Why do naphthalene balls disappear with time without leaving any solid behind?

Solution:

Naphthalene undergoes sublimation easily i.e., the change of state of naphthalene from solid to gas without the intervention of the liquid state. Thus, naphthalene balls keep on forming naphthalene vapours which disappear into the air with time without leaving any solid.

QUESTION: 6

In which state does water exist at 50°C?

Solution:

At 50°C water will be in its liquid state.

QUESTION: 7

Which property of a gas helps to fill a large volume of liquefied petroleum gas (LPG) in cylinders?

Solution:

LPG (liquefied petroleum gas) is a fuel that is made up of petroleum gas. On compressing this petroleum gas it forms liquid.

QUESTION: 8

What affects the change of state the most?

Solution:

Increases in heat energy can break attractions between particles and trigger a change of state.

For example, when water freezes water molecules are held in a crystalline structure by hydrogen bonds that form between neighboring water molecules. As heat is added to ice, some of the hydrogen bonds will be broken. This will allow more and more water molecules to move freely and the ice will melt and transition into the liquid state.

QUESTION: 9

Which of the following has the highest kinetic energy?

Solution:

Water vapours at 100 degree Celsius has more energy than liquid water at 100 degree Celsius. This is due to the fact that on converting liquid into gas, latent heat of vaporisation is required. Thus the total energy of steam is the sum of latent heat and kinetic energy whereas liquid water consists of only kinetic energy.
Hence, we can say that molecules of steam have higher energy than the molecules of liquid water.

QUESTION: 10

What happens when a liquid becomes a gas?

Solution:

The kinetic theory of matter can be used to explain how solids, liquids and gases are interchangeable as a result of increase or decrease in heat energy. When an object is heated the motion of the particles increases as the particles become more energetic.

QUESTION: 11

Kinetic energy of molecules is directly proportional to

Solution:

Kinetic Molecular Theory states that gas particles are in constant motion and exhibit perfectly elastic collisions. Kinetic Molecular Theory can be used to explain both Charles' and Boyle's Laws. The average kinetic energy of a collection of gas particles is directly proportional to absolute temperature only.

QUESTION: 12

What will be the state of a substance below its freezing point?

Solution:

The temperature below the freezing point the atoms are pressurised and get attached to one another closely which provide them a fixed volume and shape that is solid.

QUESTION: 13

How does the state of matter change during the fusion process?

Solution:

If we will take the example of ice, a solid so when melting or fusion takes place ice converts to water a liquid.

QUESTION: 14

Which of the following is incorrect about plasma?

Solution:

The color of plasma is determined by the photons, which are emitted when the electrons recombine with the ions (or when excited electrons relax into a lower energy state).

QUESTION: 15

The temperature at which a liquid changes into its gaseous form is called _________.

Solution:

It is because boiling point is a particular temp. at which a liquid starts changing into gas at the atmospheric pressure.