Melting and Freezing

Q.

What is the melting and boiling point of water?

Q.

Intermolecular forces decrease on heating because kinetic energy __________ and space between particles ____________.

Q.

Why does water expands on heating??

Q.

Does freezing point change with pressure?

Q. Boiling occurs only on the surface of the liquid.

1. True
2. False

Q.

Melting is also known as _______.

Q. Kinetic energy of molecules is highest in

1. Gases
2. Solids
3. Liquids
4. Solutions

Q.

The fixed temperature at which a liquid changes into solid state is called

1. Melting point

2. Freezing point

3. Boiling point

4. Condensation Point

Q.

Differentiate between melting and freezing phenomena.

Q.

When most of the solids, liquids, and gases are cooled, they______.

Q. Define the following terms: Fusion

Q.

The thermal expansion of solids ___ .

1. depends on original length, temperature change and material properties.

2. depends on original length only.

3. the temerature change only.

4. the thermal properties of metal only.

Q.

The changing of gas into liquid on cooling, is called__________.

1. vaporisation

2. freezing

3. melting

4. condensation

Q.

The temperature at which the solid state of a substance gets converted into liquid state is called its ____________________

Q.

What happens when a liquid is heated?

Q.

Define freezing

Q.

On heating, the intermolecular space between the molecules -----------------------.

Q. Give reason:

Q.

Under what condition, we can boil water at room temperature?

Q.

The temperature at which a gas converts to a liquid is called

1. melting point

2. boiling point

3. freezing point

4. Condensation point

Q. When water solidifies to ice then heat is:

1. Liberated
   
2. Absorbed
   
3. No change
   
4. Depending on the condition of heat absorbed or liberated.
   

Q.

The freezing point of water is

1. 0°C

2. 4°C

3. 10°C

4. 100°C

Q.

How do fusion and fission differ?

1. In fission, energy is released by splitting large nuclei, whereas in fusion, small nuclei fuse together.

2. All of the above are correct.

3. Fusion occurs with light elements; fusion occurs with heavy elements.

4. Fusion requires a great deal of energy; fission releases a great deal of energy.

Q. Water in freezing form may break rocks into pieaces due to their property of:

1. condensation
2. none of these
3. contraction on freezing
4. expansion on freezing

Q.

On decreasing temperature, a liquid turns into solid. This is:

1. condensation
2. melting
3. freezing
4. sublimation

Q.

when water in the cracks of rocks freezes, the cracks widen why?

Q. The temperature of ice can be decreased below $0^{\circ }C$ by mixing ________ in it.

1. sand
2. saw dust
3. salt
4. coal

Q. On cooling gases, temperature falls and:

1. intermolcular space between the molecules decreases
2. particles loose energy
3. intermolecular attraction increases
4. all of the above

Q. The correct statement about phase change is:

1. solid to gas is called deposition
2. liquid to solid is called freezing
3. gas to solid is called sublimation
4. solid to liquid is called vaporization
5. liquid to gas is called condensation

Q. Two identical beakers labeled as $\left(X\right)$ and $\left(Y\right)$ contain $100{cm}^3$ of water each at ${20}^{o}C$. To the water in the beaker $\left(X\right)$, $100g$ of water at $0^{o}C$ was added and stirred to mix thoroughly. To the beaker $\left(Y\right)$, $100g$ of ice at $0^{o}C$ was added and stirred till it melted into water. The water in the beaker $\left(Y\right)$ will be:

1. hotter than water in beaker $X$
2. colder than water in beaker $X$
3. lighter than water in beaker $X$
4. heavier than water in beaker $X$