Home
Class 12
CHEMISTRY
In the electrolysis of alumina, cryolite...

In the electrolysis of alumina, cryolite is added to

A

Lower the melting point of alumina

B

Increase the electrical conductivity

C

Minimise the anode effect

D

Remove the impurities from alumina

Text Solution

AI Generated Solution

The correct Answer is:
**Step-by-Step Solution:** 1. **Understanding the Problem**: The question asks why cryolite is added during the electrolysis of alumina (Al₂O₃). 2. **Properties of Alumina**: Pure alumina has two main issues: - It is a poor conductor of electricity. - It has a very high melting point of approximately 2000 °C. 3. **Challenges in Electrolysis**: Due to the high melting point, if electrolysis were to be performed on pure alumina, it would require extremely high temperatures, which could lead to the vaporization of the aluminum metal produced. 4. **Role of Cryolite**: Cryolite (Na₃AlF₆) is added to the electrolysis process for the following reasons: - **Increases Electrical Conductivity**: Cryolite enhances the conductivity of the alumina mixture, allowing for a more efficient electrolysis process. - **Lowers Melting Point**: The addition of cryolite significantly reduces the melting point of the alumina mixture, making it easier to maintain a molten state during electrolysis. 5. **Conclusion**: Therefore, the addition of cryolite in the electrolysis of alumina serves to both lower the melting point of alumina and increase its electrical conductivity, facilitating the electrolysis process. **Final Answer**: Cryolite is added to lower the melting point of alumina and increase its electrical conductivity. ---
**Step-by-Step Solution:** 1. **Understanding the Problem**: The question asks why cryolite is added during the electrolysis of alumina (Al₂O₃). 2. **Properties of Alumina**: Pure alumina has two main issues: - It is a poor conductor of electricity. - It has a very high melting point of approximately 2000 °C. ...
Doubtnut Promotions Banner Mobile Dark
|

Topper's Solved these Questions

  • GENERAL PRINCIPLES AND PROCESS OF ISOLATION OF ELEMENTS

    CENGAGE CHEMISTRY ENGLISH|Exercise Archives (Single Correct)|15 Videos

  • GENERAL PRINCIPLES AND PROCESS OF ISOLATION OF ELEMENTS

    CENGAGE CHEMISTRY ENGLISH|Exercise Archives (Fill In The Blanks)|4 Videos

  • GENERAL PRINCIPLES AND PROCESS OF ISOLATION OF ELEMENTS

    CENGAGE CHEMISTRY ENGLISH|Exercise Archives (Linked Comprehension)|3 Videos

  • ELECTROCHEMISTRY

    CENGAGE CHEMISTRY ENGLISH|Exercise Archieves Subjective|35 Videos

  • GRIGNARD REAGENTS AND ORGANOMETALLIC REAGENTS

    CENGAGE CHEMISTRY ENGLISH|Exercise Exercises Archives (Linked Comprehension)|1 Videos

Similar Questions

Explore conceptually related problems

Explain the following (i) Excess of carbon is added to zinc metallurgy. (ii) In the elctrolysis of alumina, cryolite is added to alumina. (iii) Coke does not cause reduction of Al_(2)O_(3) . (iv) Gold is soluble in aquaregia, silver is not.

Aluminium is extracted from bauxite by the electrolysis of aluminium oxide dissolved in cryolite. Now answer the following question: Write the reactions at cathode in the electrolytic reduction of alumina.

Aluminium is extracted from bauxite by the electrolysis of aluminium oxide dissolved in cryolite. Now answer the following question: Write the formula of cryolite.

Explain why : In the electrolysis of molten alumina, the carbon anode is gradually consumed.

Explain why : In the electrolysis of alumina using the Hall Heroult's Process, the electrolyte is covered with powdered coke.

Aluminium is extracted from bauxite by the electrolysis of aluminium oxide dissolved in cryolite. Now answer the following question: Name the process used for the purification of bauxite.

Aluminium is extracted from bauxite by the electrolysis of aluminium oxide dissolved in cryolite. Now answer the following question: Why is so much graphite required for this electrolytic process?

Aluminium is extracted from bauxite by the electrolysis of aluminium oxide dissolved in cryolite. Now answer the following question: Write the equation for the action of heat on aluminium hydroxide.

Aluminium is extracted from bauxite by the electrolysis of aluminium oxide dissolved in cryolite. Now answer the following question: Write down the word which correctly completes the following sentence: "By dissolving aluminium oxide in cryolite a __________ solution is produced. (nonconducting/conducting)"

Aluminium is extracted from bauxite by the electrolysis of aluminium oxide dissolved in cryolite. Now answer the following question: When bauxite is treated with sodium hydroxide solution, what happens to the aluminium oxide and iron (III) oxide?

Home
Profile