Hygroscopy, Efflorescence, Deliquescence

Q.

Define Hygroscopy? Give an example of Hygroscopic substance.

Q.

The chemical formula for hydrated copper sulphate is $CuS{O}_4.5H_{2}O$. What is the 5 molecules of water associated with the salt called?

1. Water of hydration

2. Anhydrous water

3. Water of crystallisation

4. Molecular water

Q.

Give an example of a hygroscopic substance.

Q. Which of the following gas is absorbed by potassium hydroxide?

1. Carbon dioxide gas
2. Oxygen gas
3. All of the above
4. Carbon monoxide

Q.

Is salt a mineral?

Q.

Potash alum is a double salt having the chemical formula ${\mathrm{K}}_2{\mathrm{SO}}_4.{\mathrm{Al}}_2{\left({\mathrm{SO}}_4\right)}_3.24{\mathrm{H}}_2\mathrm{O}$ It dissolves in water to form a clear solution.

Will Potash alum be wet in its solid state due to the presence of water of crystallization in large numbers?

Q. What are the chemicals used in the laboratory preparation of chlorine?

1. Potassium permanganate
   
2. Hydrochloric acid
   
3. Potassium chloride
   
4. Carbonic acid
   

Q.

The solubility of calcium hydroxide ___ with rise in temperature. (increases/decreases)

Q.

Define Hygroscopic substance .

Q. salts contain definite number of water molecules in their crystalline structure.

1. Hydrated
2. Anhydrous
3. Efflorescent

Q.

Which among the following categories of substances absorbs atmospheric moisture and forms a saturated solution?

1. Deliquescent substances

2. Hygroscopic substances

3. Anhydrous substances

4. Efflorescent substances

Q. Which of the following is not an example of hygroscopic substance?

1. Zinc Chloride
2. Potassium Hydroxide
3. Calcium chloride
4. Magnesium Chloride

Q.

What are hydrated salts? Explain with example.

Q. Define hygroscopic, efflorescence, and deliquescence. [3 marks]

Q.

13. Match the following.

(a) A ⇢II , B ⇢ III, C ⇢ IV, D ⇢ I

(b) A ⇢ IV, B ⇢ III, C ⇢ I, D ⇢II

(c) A ⇢ III, B ⇢ IV, C ⇢ II, D ⇢ I

(d) A ⇢ III, B ⇢ IV, C ⇢ I, D ⇢ II

Column 1	Column 2
CuSO4	Deliquescent
Na2CO3.10H2O	Hygroscopic
concentrated H2SO4	Efflorescent
ZnCl2	Anhydrous salt

Q. Match the following substances with their corresponding properties.

1. Deliquescence
2. Efflorescence
3. Hygroscopy

Q.

Name the drying agent which is used during the preparation of FeCl₃ from Iron and Chlorine?

Q.

State the electrode reaction at the anode during electrolysis of Aqueous nickel sulphate solution using nickel anode

Q. Give two examples for each of the following:

$\left(c\right)$. Drying agents

Q.

Name two substances which do not contain water of crystallisation?

Q.

Which of the following is used as a drying agent:-

1. Sulphuric acid

2. Blue vitriol

3. Washing soda

4. Glauber's salt

Q. A hygroscopic substance is _________.

1. Sulfuric acid
2. Water
3. Washing soda
4. Hydrogen

Q.

Koel was not able to understand that why water molecules are added with a dot at the end of most salts. Help her with this.

1. To highlight that the salt is anhydrous

2. To highlight the hydrate part of the salt

3. Water molecules are never bonded directly

4. To highlight that the salt is dissolved in water

Q.

What is the term used for allotropes of carbon which are cylindrical nanostructure and extremely strong, thermally conductive, and very toxic?

1. Nanotubes

2. Nanobulbs

3. Microtubules

4. Nanofibre

Q.

By giving example define the following terms: Deliquescence

Q.

What is hygroscopy?

Q. Answer the following question relating your answers only -to salts in the list given below:

Q. During the preparation of hydrogen chloride gas on a humid day, the gas is usually passed through two guard tube containing calcium chloride. The role of calcium chloride in the guard tube is:

1. it absorbs the evolved gas
2. it moisten the gas
3. it absorbs $C{l}^{-}$ ions form the gas evolved
4. it absorbs moisture from the gas

Q. The process by which a substance absorbs moisture upon exposure to the atmosphere is called:

1. efflorescence
2. dehydrogenation
3. desalination
4. deliquescence

Q. Which of the following is not true about hygroscopic substances?

1. Because of their affinity for atmospheric moisture, hygroscopic materials might require storage in sealed containers.
2. When added to foods or other materials for the express purpose of maintaining moisture content, such substances are known as fumectants.
3. Hygroscopic substances include cellulose fibers (such as cotton and paper), sugar, caramel, honey.
4. All of the above.