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प्रश्न
What is the difference between calcination and roasting?
Compare roasting and calcination.
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उत्तर
| Roasting | Calcination | |
| (1) | The ore is heated in the excess of air. | The ore is heated in the absence of air. |
| (2) | Volatile impurities are removed as oxides (SO2, P2O5, As2O3) and the ore becomes porous and more reactive. | Moisture and organic impurities are removed and the ore becomes porous and more reactive. |
| (3) | Sulphide ores are roasted, so SO2 is given off. \[\ce{2ZnS + 3O2 ->[800^\circ-900^\circ C]2ZnO + 2SO2}\] |
Carbonate and hydrated ores are calcined and CO2 or water vapour are given off. \[\ce{ZnCO3 -> ZnO + CO2}\] |
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संबंधित प्रश्न
Metallic oxides of zinc, magnesium and copper were heated with the following metals.
| Metal | Zinc | Magnesium | Copper |
| Zinc oxide | – | – | – |
| Magnesium oxide | – | – | – |
| Copper oxide | – | – | – |
In which cases will you find displacement reactions taking place?
The process by which sulphide ore is concentrated.
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Fill in the following blank with suitable word:
Bronze is an alloy of copper and .........
Name two metals which are found in nature mainly in the free state (as metallic elements).
Name three other metals which are extracted in a manner similar to sodium.
An important ore of zinc metal is:
(a) calamine
(b) cuprite
(c) pyrolusite
(d) haematite
Which metal can be extracted from the following ore?
Haematite
Give reasons, why aluminum is used in:
making alloys
Define the following term.
Gangue
Answer the following question :
What is the difference between calcination and roasting.
Draw a well-labelled diagram of extraction of Aluminium. Write the anode reaction in electrolytic reduction of Alumina.
Atomic number of aluminium is _______ and its electronic configuration is _______.
Sulphide ores : Roasting : : Carbonate ores : _______
Bauxite reacts with sodium hydroxide in the Bayer’s process.
Explain the concept of Calcination.
Explain Bayer’s process.
Complete flow chart given below.
Explain in brief types of extraction of highly reactive metals according to their reactivity.
The highly reactive metals like Sodium, Potassium, Magnesium, etc. are extracted by the ____________.
