Advertisements
Advertisements
Question
Explain and give reasons why aluminium vessels should not be cleaned with powders containing alkalis.
Solution
Aluminium vessels should not be cleaned with powders containing alkalis because aluminium reacts with alkalis to form respective aluminate and hydrogen as:
\[\ce{2Al + 2NaOH + 2H2O -> 2NaAlO2 + 3H2}\]
APPEARS IN
RELATED QUESTIONS
Answer the following questions with respect to the electrolytic process in the extraction of aluminum:
Explain why powdered coke is sprinkled over the electrolytic mixture.
For the substance given below, describe the role played in the extraction of aluminium.
Cryolite
Name the constituents of Bronze.
For bauxite, explain its significance in the extraction of aluminium.
For sodium hydroxide, explain its significance in the extraction of aluminium.
In order to obtain 1 tonne of aluminium, the following inputs are required: 4 tonnes of bauxite, 150 kg of sodium hydroxide and 600 kg of graphite. The aluminium compound in bauxite is aluminium oxide and the main impurity is iron (III) oxide. Aluminium is obtained by the electrolysis of aluminium oxide dissolved in cryolite.
- Write the formula of cryolite.
- Write down the word which correctly completes the following sentence.
By dissolving aluminium oxide in cryolite, a ______ (conducting/non-conducting) solution is produced. - Why is so much graphite required for the electrolytic process?
- Write the equation for the reaction which takes place at the cathode.
- What is cathode made up of?
Name the following:
The materials used as electrodes in the electrolytic extraction of aluminium.
A to F below relate to the source and extraction of either zinc or aluminium.
- Bauxite
- Coke
- Cryolite
- Froth floatation
- Sodium hydroxide solution
- Zinc blende
Fill in the blanks using the most appropriate words from A to F:
(i) The ore from which aluminium is extracted must be treated with ______ so that pure aluminium oxide can be obtained.
(ii) Pure aluminium oxide is dissolved in ______ to make a conducting solution.
State the relevant reason for the following:
Graphite anodes are continuously replaced during the electrolysis of alumina.
Given below in column A is a schematic diagram of the electrolytic reduction of alumina. Identify the parts labelled as A, B and C with the correct options from the Column B.
| column A | column B | |
 |
1. | Platinum |
| 2. | Anode | |
| 3. | Cathode | |
| 4. | Electrolyte mixture | |
| 5. | Bauxite |
