One or More than One Options Correct TypeDirection (Q. Nos. 11-15) This section contains 5 multiple choice questions. Each question has four choices (a), (b), (c) and (d), out of which ONE or MORE THAN ONE are correct.Q.Purification of alumina is calleda)Baeyer’s procesb)Hall processc)Mond’s procesd)Hoope’s procesCorrect answer is option 'A'. Can you explain this answer?

Question

One or More than One Options Correct TypeDirection (Q. Nos. 11-15) This section contains 5 multiple choice questions. Each question has four choices (a), (b), (c) and (d), out of which ONE or MORE THAN ONE are correct.Q.Purification of alumina is calleda)Baeyer&rsquo;s procesb)Hall processc)Mond&rsquo;s procesd)Hoope&rsquo;s procesCorrect answer is option 'A'. Can you explain this answer?

Answer

Baeyer's process is used to obtain pure alumina. as sodium silicate, leaving behind the impurities. The resulting solution is filtered, and cooled and neutralized with carbon dioxide to get aluminium hydroxide as precipitate leaving sodium silicate in the solution.

Answer

_{The correct answer is Option A.
The purification of alumina can be done by Baeyer's process.
In Baeyer’s process, impure bauxite is converted into pure alumina. The conversion process involves mainly three reactions:
1. Concentrated sodium hydroxide solution is heated with amphoteric bauxite at a temperature of 150 to 200°C under pressure to get sodium aluminate.
2. Sodium aluminate is then diluted with water at a temperature of 50 to 60°C. Thus, sodium aluminate gets hydrolysed to form solid aluminium hydroxide and sodium hydroxide.
3. Finally, dried aluminium hydroxide precipitate is ignited at a temperature of 1100°C to remove water molecules to get alumina.}

Answer

Purification of alumina
Alumina is purified using various processes, and one of the methods is known as the Baeyer's process.

Baeyer's process
- In the Baeyer's process, impure alumina is dissolved in a hot concentrated solution of sodium hydroxide.
- The impurities present in the alumina are converted into sodium aluminate, which is soluble in the solution.
- The solution is then filtered to remove the insoluble impurities.
- Carbon dioxide is then passed through the solution, which leads to the precipitation of pure alumina hydrate.
- The precipitated alumina hydrate is then calcined to obtain pure alumina.
Therefore, the purification of alumina is called the Baeyer's process.

Top Courses for Class 12

Suggested Free Tests

Related Content

Schools

Competitive Examinations

Quick Access Links

Technical Exams