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प्रश्न
Name the gas in air which tarnishes silver articles slowly.
उत्तर
Hydrogen sulphide gas in the air tarnishes silver articles slowly. Silver reacts with hydrogen sulphide gas in the air and forms a thin black layer of silver sulphide (Ag2S) on it. Therefore, silver jewellery or ornaments become dull due to the formation of silver sulphide coating on their surface.
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संबंधित प्रश्न
Which metal is extracted from cinnabar ore?
Name two ores of zinc. Write the names of the chemical compounds present in them and give their chemical formulae.
The articles made of silver metal become dark on prolonged exposure to air. This is due to the formation of a layer of its:
(a) oxide
(b) hydride
(c) sulphide
(d) carbonate
Distinguish between ‘roasting’ and ‘calcination’. Which of these two is used for sulphide ores and why?
Give the chemical formula of :
Sodium aluminate
Name the following:
The process of heating an ore to a high temperature in the presence of air.
Write the molecular formulae of the following compound.
Sodium aluminate
Explain the reactions of nonmetals with water with the help of examples.
Explain the characteristics of ionic compounds.
Which of the following metals exist in their native state in nature?
- Cu
- Au
- Zn
- Ag
