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प्रश्न
Identify the process given in following passage and draw neat labelled diagram showing the process.
Electrolysis of molten mixture of alumina (melting point > 20000C) is done in a steel tank. The tank has a graphite lining on the inner side. This lining does the work of a cathode. A set of graphite rods dipped in the molten electrolyte works as anode. Cryolite (Na3AlF6) and fluorspar (CaF2) are added in the mixture to lower its melting point upto 10000C.
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उत्तर
Electrolytic reduction of Alumina :
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संबंधित प्रश्न
In the extraction of aluminium: Draw the diagram for the extraction of aluminium.
How many carats is pure gold? Why is pure gold not suitable for making ornaments?
Why does a new aluminium vessel lose shine so soon after use?
Manganese metal is extracted from manganese dioxide by a reduction process by making use of ______.
A black metal oxide XO2 is used as a catalyst in the preparation of oxygen gas from potassium chlorate. The oxide XO2 is also used in ordinary dry cells. The metal oxide XO2 cannot be reduced satisfactorily with carbon to form metal X.
- Name the metal X.
- Name the metal oxide XO2.
- Which reducing agent can be used to reduce XO2 to obtain metal X?
- Name another metal which can also be extracted by the reduction of its oxide with the above reducing agent.
Give reasons, why aluminum is used in:
painting electric and telegraphic poles
Give the chemical formula of :
Cryolite
Answer the following questions based on the extraction of aluminium from alumina by Hall - Heroult’s Process :
What is the function of cryolite used along with alumina as the electrolyte?
Name the following:
The process of heating a substance very strongly in such a way that it does not combine with oxygen.
How an ore is concentrated by froth floatation process?
How are metals refined by the electrolytic methods?
Compare the properties of a typical metal and a non- metal on the basis of the following:
(a) electronic configuration
(b) nature of oxides
(c) oxidizing or reducing action
(d) conductivity of heat and electricity
Correct the following statement :
Copper reacts with nitric acid to produce nitrogen dioxide.
Answer the following question :
What is the difference between calcination and roasting.
Name the methods by which concentrated ore is converted to metallic oxide.
Define roasting.
_______ is the least reactive metal.
Right or wrong sentence?
The electrolysis of alumina combines fluorite and cryolite to increase the solubility in the precipitation method.
Why should the metal sulphides and carbonates be converted to metal oxides in the process of extraction of metal from them?
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?
