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प्रश्न
Define roasting.
उत्तर
Roasting is the process of heating concentrated ore to a high temperature in the presence of air.
संबंधित प्रश्न
A zinc ore gave CO2 on treatment with a dilute acid. Identify the ore and write its chemical formula.
Silver metal does not combine easily with oxygen but silver jewellery tarnishes after some time. How?
How is manganese extracted from manganese dioxide, MnO2? Explain with the help of an equation.
Name one ore of copper (other than cuprite). Which compound of copper is present in this ore? Also, write its chemical formula.
In an electrolytic tank, aluminium metal is being extracted by the electrolysis of molten aluminium oxide using carbon electrodes. It is observed that one of the carbon electrodes is gradually burnt away and has to be replaced.
(a) Which carbon electrode (cathode or anode) is burnt away?
(b) Why is this carbon electrode burnt away?
When an object made of metal A is kept in air for a considerable time, it loses its shine and becomes almost black due to the formation of a layer of substance B. When an object made of another metal C is kept in damp air for a considerable time, it gets covered with a green layer of substance D. Metal A is the best conductor of electricity whereas metal C is the next best conductor of electricity.
(a) What is metal A?
(b) What is metal C?
(c) Name the substance B.
(d) Name the substance D.
Define the term : Slag
State the property of the metal being utilized in the following :
| Use of metal | Property |
| Zinc in Galvanization | |
| Aluminium in Thermite welding |
Explain the characteristics of ionic compounds.
Explain Bayer’s process of concentration of bauxite with a chemical equation.
