Sublimation

Q.

Use the frosty fizz in a sentence

Q.

Give reason why a crystal of iodine on slow heating in a closed flask, turns into vapour and fills the complete flask.

Q.

Define the following term :

Supernatant liquid

Q.

Dry ice is an example of-----process.

1. evaporation

2. crystallisation

3. sublimation

4. purification

Q.

Naphthalene balls disappear with time without leaving any solid. Give reason

Q.

Does ammonium chloride sublime?

Q.

The process by which a solid directly converts into its gaseous state is called

1. Evaporation

2. Condensation

3. Sublimation

4. Ebullition

Q.

Identify a white solid formed when carbon dioxide solidifies on cooling temperature.

Q. What is sublimation? Give a few examples of substances that undergo sublimation.

Q.

Define the process of change of a liquid to a gas.

Q.

4. Describe an experiment for separation of pure ammonium chloride from a mixture of common salt and ammonium chloride.

Q.

How is sublimation different from solidification ?

Q. Identify the phenomenon due to which the size of solid balls of naphthalene or camphor get reduced after few weeks.

1. Evaporation
2. Melting
3. Condensation
4. Sublimation

Q.

Name a violet substance which changes to violet vapours.

Q.

In the process of sublimation to separate a mixture of common salt and ammonium chloride, common salt sublimes on heating whereas ammonium chloride does not.

1. True
2. False

Q. Which of the following substances do not undergo sublimation?

1. Ice
2. Iron
3. Oxygen
4. Camphor
5. Iodine
6. Sponge
7. Naphthalene ball
8. Wood

Q. Write the steps to separate a mixture containing stones, sand, and ammonium chloride.

Q.

which gas directly changes into solid through sublimation?

Q.

A mixture of sand and iodine can be separated by sublimation.

1. True
2. False

Q. Identify the substance that can undergo sublimation.

1. Naphthalene

2. CO₂

3. Ice

4. N₂

Q. To get her house whitewashed, an officer bought 10 kg of quicklime from the market and dissolved it in 30 L of water. She noticed that the mixture appeared to be boiling even though it was not being heated. Choose the corresponding product formed and the type of reaction involved.

1. Product: Limestone
   Type of reaction: Endothermic
2. Product: Limewater
   Type of reaction: Endothermic
3. Product: Slaked lime
   Type of reaction: Exothermic
4. Product: Limestone
   Type of reaction: Exothermic

Q.

________ separates fine solid particles from a liquid-solid mixture by rotating the mixture at high speed.

Q. A mixture contains camphor and common salt. Camphor is known to go to the gas phase upon slight heating. So which process can be used to separate common salt from camphor?

1. Sublimation
2. Condensation
3. Freezing
4. Melting

Q.

Define sublimation.

Q.

…………………….. [ sublimation/ Evaporation] is a process of solid directly converting into gases

Q. The process by which solid ${CO}_2$ is directly converted to its gaseous form is called:

1. Evaporation
2. Decomposition
3. Sublimation
4. None of the above

Q.

What are the methods used to speed up the rate of dissolving?

1. Distilling and sudden cooling

2. Fractionating and then cooling

3. Heat, stir, and shake

4. None of the choices

Q.

Which of the following property leads to the process of distillation?

1. Difference in freezing points of two liquids

2. Both A and B

3. None of the above

4. Difference in boiling points of two liquids

Q. Which process do napthalene balls undergo when left open?

Q. Size of naphtalene balls decreases.

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