Condensation

Q. What is distilled water

Q.

Which substances do not change their state ?

Q. Water in its gaseous form is known as .

1. dew
2. water vapour
3. fog

Q.

Why do we feel extra cold when snow starts melting?

Q.

What is the boiling point of water in celsius ?

1. 150${}^{\circ }$C

2. 70${}^{\circ }$C

3. 100${}^{\circ }$C

4. 98${}^{\circ }$C

Q. Can a solid turn into gas?

Q. Deposition occurs when the temperature , whereas sublimation occurs when the temperature .

1. increases
2. decreases
3. remains constant
4. is zero

Q.

1. Water can be changed from one state to another by ______ or ________.

Q. Give the reason why clothes dry faster when the sunshine?.

Q. Can a solid turn into gas?

Q. Dew drops found in the leaves of plants in cold mornings is due to ______.

1. evaporation
2. sedimentation
3. condensation
4. filtration

Q. Can a solid turn into gas?

Q. Which phenomenon occurs during drying of wet clothes?

1. Evaporation
2. Condensation
3. Freezing
4. Boiling

Q. Identify the method by which chalk powder and water can be separated.

1. Winnowing
2. Threshing
3. Filtration
4. Sedimentation

Q. Define:
(b) intermolecular forces of attraction

Q.

Explain the differences between pure air and polluted air. [3 MARKS]

Q. Identify the liquid-in-gas type of mixture from the following.

1. Dissolved carbon dioxide in water
2. Droplets of water in air
3. Dissolved oxygen in water
4. Nitrogen in air

Q.

Chemical changes are mostly irreversible.

1. True

2. False

Q. Identify the method by which chalk powder and water can be separated.

1. Winnowing
2. Sedimentation
3. Threshing
4. Filtration

Q. An increase in temperature decreases the rate of evaporation.

1. False
2. True

Q. Which of the following techniques is not used to separate a sand-salt mixture?

1. Filtration
2. Evaporation
3. Winnowing
4. Decantation

Q.

Applying pressure and reducing temperature can lead to

1. Evaporation of gases

2. Liquefaction of gases

3. Corrosion of gases

4. Diffusion of gases

Q. Evaporation is the process by which a liquid changes into vapour, by absorbing heat.

1. False
2. True

Q. Identify the method by which chalk powder and water can be separated.

1. Filtration
2. Sedimentation
3. Threshing
4. Winnowing

Q. An increase in temperature decreases the rate of evaporation.

1. True
2. False

Q. Can a solid turn into gas?

Q. The phenomenon of change from one state of matter to another and then back to the original state is called ___________.

1. changing the state of matter
2. inter-conversion of states of matter
3. all of the above
4. converting the state of matter

Q. Which of the following method is used to separate the mixture of petrol and water?

1. Decantation
2. Evaporation
3. Condensation
4. Sieving

Q. Given below are few substances with their boiling points at room temperatures. Which amongst them would evaporate the fastest at room temperature $\left({25}^{\circ }C\right)$?

1. Petrol: ${210}^{\circ }C$
2. Water: ${100}^{\circ }C$
3. Acetone: ${56}^{\circ }C$
4. Sanitizer: ${78}^{\circ }C$

Q. Which amongst the following parameters cannot be used to identify the occurrence of a chemical reaction?

1. Change in smell
2. Change in shape
3. Absorption of heat
4. Formation of gas