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प्रश्न
Explain the following reaction with the balanced equation.
Dry aluminium hydroxide is ignited at 1000 °C
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उत्तर
When dry aluminium hydroxide is calcined by at 1000 °C, pure aluminium oxide, called alumina is obtained.
\[\ce{\underset{\text{Aluminium hydroxide}}{2Al(OH)_{3(s)}} ->[heat][1000 °C] \underset{\text{Aluminium oxide}}{Al2O_{3(s)}} + \underset{\text{Water vapour}}{3H2O_{(g)}}}\]
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संबंधित प्रश्न
Explain why, carbon cannot reduce oxides of sodium or magnesium.
Name the method by which aluminium metal is extracted.
Name the metal which is extracted from the ore called ‘rock salt’.
Calamine ore can be used to extract one of the following metals. This metal is:
Calamine ore can be converted into zinc oxide by the process of ______.
State three objectives achieved during the roasting of ores.
Give the chemical formula of :
Cryolite
Name the following:
The mixture of materials fed into a furnace to extract a metal.
Name the following:
The substance added to get rid of gangue in the extraction of metal.
Name the following:
The process in which an ore is heated in air so that oxygen gets added to it to form the oxides.
The following questions relate to the extraction of aluminium by electrolysis.
Explain why it is necessary to renew the anode periodically.
Complete the incomplete statement with missing word:
Non-metals form acidic oxides while metals form ______.
Name:
The allotrope of the non-metal carbon which conducts electricity.
To protect iron from rusting, it is coated with a thin layer of zinc. Name the process.
Write the name.
The process of strong heating of carbonate ores in insufficient air–
Write the molecular formulae of the following compound.
Cryolite
Write the molecular formulae of the following compound.
Fluorspar
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.
The given reaction shows one of the processes to extract the metals like Iron and Manganese.
\[\ce{MnO2(s) + Al(s) -> Mn(l) + Al2O3(s) + Heat}\]
Identify the substance oxidised and reduced in the above reaction.
