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प्रश्न
Answer the following question :
What is the difference between calcination and roasting.
उत्तर
| Calcination | Roasting |
| 1. The ore is heated in the absence of air | 1. The ore is heated in excess of air. |
| 2. Moisture and organic impurities are removed, and the ore becomes porous and more reactive. |
2. Volatile impurities are |
| 3. Carbonate and hydrated ores are calcined, and CO2 or water vapour is given off. ZnCO3 → ZnO + CO2 |
3. Sulphide ores are roasted, so SO2 is given off. \[\ce{2ZnS + 3O2 ->[80°-90°] 2ZnO + 2S}\] |
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संबंधित प्रश्न
Name two metals which are found in nature in the free state.
What is meant by the 'concentration of ore'?
Explain given equation, what happens when ZnCO3 is heated in the absence of air?
Name one ore of sodium. Name the sodium compound present in this ore and write its chemical formula.
Calamine ore can be converted into zinc oxide by the process of:
(a) dehydration
(b) roasting
(c) calcination
(d) sulphonation
Some metallic oxides can be reduced by hydrogen, carbon and carbon monoxide and some cannot. Explain.
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
Aluminium oxide is _______ oxide.
Electrical wires have a coating of an insulting material. The material, generally used is
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.
