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प्रश्न
Write the name.
The molecular formula of main ore of aluminium –
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उत्तर
The molecular formula of main ore of aluminium – Al2O3•nH2O
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संबंधित प्रश्न
Give reasons.
Aluminium is a highly reactive metal, yet it is used to make utensils for cooking.
Name one metal which is extracted by reduction with aluminium.
What is the difference between a mineral and an ore?
An ore of manganese metal is:
(a) bauxite
(b) haematite
(c) cuprite
(d) pyrolusite
Rock salt is an ore of one of the following metals. This metal is:
(a) Mn
(b) Na
(c) Fe
(d) Cu
Distinguish between ‘roasting’ and ‘calcination’. Which of these two is used for sulphide ores and why?
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.
Define the following term.
Mineral
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?
Write equations for each of the above metal which reacts with water.
Answer the following question :
What is the difference between calcination and roasting.
Define roasting.
Write the name.
Metals which are amphoteric in nature.
Mercury, silver, gold are highly reactive metals.
In the electrolytic method, a layer of highly active metal is applied to a less active metal.
The electrolysis of alumina involves the use of fluorspar and cryolite to increase the melting point.
Explain the following reaction with the balanced equation.
Zinc sulphide is heated strongly in excess of air
Explain in brief types of extraction of less reactive metals according to their reactivity.
The highly reactive metals like Sodium, Potassium, Magnesium, etc. are extracted by the ____________.
During extraction of metals, electolytic refining is used to obtain pure metals.
(a) Which material will be used as anode and cathode for refining of silver metal by this process?
(b) Suggest a suitable electrolyte also.
(c) In this electrolytic cell, where do we get pure silver after passing electric current?
