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प्रश्न
Give reason.
Copper and brass utensils should be tinned.
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उत्तर
Copper and brass materials also undergo corrosion, resulting in the formation of a greenish layer on this surface. When the surface of copper or brass is contacted by air or water, it results in corrosion, and to prevent this, the process of tining is used. In this process, copper and brass articles are coated with tin.
संबंधित प्रश्न
In one method of rust prevention, the iron is not coated with anything. Which is this method?
If copper is kept exposed to damp air for a considerable time, it gets a green coating on its surface. This is due to the formation of:
(a) hydrated copper sulphate
(b) copper oxide
(c) basic copper carbonate
(d) copper nitrate
Explain with reason:
Roasting is carried out on sulphide ores and not on carbonate ores.
No chemical reaction takes place when granules of a solid, A, are mixed with the powder of another solid, B. However when the mixture is heated, a reaction takes place between its components. One of the products, C, is a metal and settles down in the molten state while the other product, D, floats over it. It was observed that the reaction is highly exothermic.
(i) Based on the given information make an assumption about A and B and write a chemical equation for the chemical reaction indicating the conditions of reaction, physical state of reactants and products and thermal status of reaction.
(ii) Mention any two types of reactions under which above chemical reaction can be classified.
Find the odd man out:
Write a short note on Alloying.
Draw a neat labelled diagram.
Anodizing
The process of coating the surface of the metal with a thin layer of zinc is called ______
Explain the following:
Lime water turns milky on passing carbon dioxide gas into it.
Give scientific reasons.
Silver amalgam is used for filling dental cavities.
