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प्रश्न
Name the following:
A metal which is always present in the amalgam.
उत्तर
Mercury
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संबंधित प्रश्न
Explain why In the electrolysis of alumina using the Hall Heroult's Process the electrolyte is covered with powdered coke
Name the process by which the refining of aluminium is done ?
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?
Aluminium is extracted from its chief ore, bauxite. The ore is first purified and then the metal is extracted from it by electrolytic reduction.
Write an equation for the reaction which takes place at the anode during the extraction of aluminium by the electrolytic process.
Name the ore from which aluminium is extracted.
For the substance listed below, explain its role in the extraction of aluminium: Graphite
Aluminium is extracted from its chief ore bauxite. The ore is first purified and then the metal is extracted from it by electrolytic reduction.
Mention one reason for the use of aluminium in thermite welding. Which particular property of cast iron makes it unsuitable for the construction of bridges?
The following is an extract from 'Metals in the Service of Man, Alexander and Street/Pelican 1976':
| 'Alumina (aluminium oxide) has a very high melting point of over 2000°C so that it cannot readily be liquefied. However, conversion of alumina to aluminium and oxygen, by electrolysis, can occur when it is dissolved in some other substance.' |
- Which solution is used to react with bauxite as a first step in obtaining pure aluminium oxide?
- The aluminium oxide for the electrolytic extraction of aluminium is obtained by heating aluminium hydroxide. Write the balanced chemical equation for this reaction.
- Name the element which serves both as the anode and the cathode in the extraction of aluminium.
- Write the balanced chemical equation for the reaction that occurs at the cathode during the extraction of aluminium by electrolysis.
- Give the balanced chemical equation for the reaction which occurs at the anode when aluminium is purified by electrolysis.
Name the alloy used for the following purpose.
Making medals
The following sketch illustrates the process of conversion of Alumina to Aluminium:
- Name the constituent of the electrolyte mixture which has a divalent metal in it.
- Name the powdered substances ‘X’ sprinkled on the surface of the electrolyte mixture.
- What is the name of the process?
- Write the reactions taking place at the electrodes ‘Y’ (anode) and ‘Z’ (cathode), respectively.
