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प्रश्न
Observe the figure and answer the following.
- Write the name of the method.
- What is used as anode and cathode in this method?
- Write the molecular formula and use of cryolite.
- Write anode reaction.
- Write cathode reaction.
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उत्तर
- The method shown is an electrolytic reduction of alumina.
- A set of graphite rods dipped in the molten electrolyte acts as the anode. and the graphite lining acts as a cathode.
- Molecular formula of cryolite: Na3AlF6
Use of cryolite: Addition of cryolite reduces the melting point of alumina to about 1000 °C. - Anode reaction: \[\ce{2O^2+ -> O2 + 4e^-}\]
- Cathode reaction: \[\ce{Al^3+ + 3e^- -> Al_{(l)}}\]
APPEARS IN
संबंधित प्रश्न
Name the following:
Main ore of aluminium.
Define the Ore.
How many carats is pure gold? Why is pure gold not suitable for making ornaments?
Explain why, an aqueous solution of sodium chloride is not used for the electrolytic extraction of sodium metal.
Which of the following is an ore of mercury metal?
Calamine ore can be used to extract one of the following metals. This metal is:
Zinc blende ore can be converted into zinc oxide by the process of ______.
Name the following:
The mixture of materials fed into a furnace to extract a metal.
Define the term:
Flux
What is meant by concentration of ores?
The following question relate to the extraction of aluminium by electrolysis.
Give the equation for the reaction which takes place at the cathode.
Complete the incomplete statement with missing word:
Metals form positive ions while non- metals ______.
Name a non- metal that has a metallic luster and sublimes on heating.
Atomic number of aluminium is _______ and its electronic configuration is _______.
Identify who I am!
Ore of Aluminum- ______
Explain the concept of Roasting.
Explain the following reaction with the balanced equation.
Ferric oxide is reacted with aluminium.
Explain concept with example/explain with the help of a balanced equation.
Calcination
Two ores A and B were taken. On heating ore A gives CO2 whereas, ore B gives SO2. What steps will you take to convert them into metals?
On the basis of reactivity metals are grouped into three categories:
- Metals of low reactivity
- Metals of medium reactivity
- Metals of high reactivity
Therefore metals are extracted in pure form from their ores on the basis of their chemical properties.
Metals of high reactivity are extracted from their ores by electrolysis of the molten ore.
Metals of low reactivity are extracted from their sulphide ores, which are converted into their oxides. The oxides of these metals are reduced to metals by simple heating.
(a) Name the process of reduction used for a metal that gives vigorous reaction with air and water both.
(b) Carbon cannot be used as a reducing agent to obtain aluminium from its oxide? Why?
(c) Describe briefly the method to obtain mercury from cinnabar. Write the chemical equation for the reactions involved in the process.
OR
(c) Differentiate between roasting and calcination giving chemical equation for each.
