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प्रश्न
The given reaction shows one of the processes to extract the metals like Iron and Manganese.
\[\ce{MnO2(s) + Al(s) -> Mn(l) + Al2O3(s) + Heat}\]
Give a reason why Aluminium is preferably used in thermite reactions.
उत्तर
Aluminium is preferably used in thermite reactions as it is placed above Fe and Mn in the reactivity series of metals.
OR
Al is more reactive than Fe/ Mn.
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संबंधित प्रश्न
Name the following: Main ore of aluminium.
How is copper extracted from its sulphide ore? Explain the various steps supported by chemical equations. Draw labelled diagram for the electrolytic refining of copper.
Name the gas produced when calamine ore is calcined.
Name two ores of zinc. Write the names of the chemical compounds present in them and give their chemical formulae.
Manganese metal is extracted from manganese dioxide by a reduction process by making use of:
(a) carbon
(b) hydrogen
(c) electrolysis
(d) aluminium
Give the principles of the froth floatation process.
Complete the incomplete statement with missing word:
Non-metals form acidic oxides while metals form ______.
Explain Bayer’s process.
Explain in brief types of extraction of less reactive metals according to their reactivity.
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.
