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प्रश्न
If copper is kept open in air, it slowly loses its shining brown surface and gains a green coating. It is due to the formation of
विकल्प
CuSO4
CuCO3
Cu(NO3)2
CuO
उत्तर
CuCO3
Explanation -
Copper metal kept open in the air, slowly undergoes the process of corrosion to form a characteristic blue-green coating on top of the metal surface. The corrosion of copper metal in air occurs in several steps :
`4"Cu"("s") + "O"_2("g") -> 2"Cu"_2"O"("s"),` red colour
`"Cu"_2"O"("s") + "O"_2("s") -> 2"CuO"("s"),` black colour
`2"CuO"("s") + "CO"_2("g") + "H"_2"O"("l") -> "CuCO"_3("s") + "CuCO"_3("s") + "Cu"("OH")_2("s"),` green colour
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संबंधित प्रश्न
What are amphoteric oxides?
Diamond : electric insulator : : _______ : electric conductor
Example of an amphoteric oxide is:
Which one of the following metals does not react with cold as well as hot water?
Generally, metals react with acids to give salt and hydrogen gas. Which of the following acids does not give hydrogen gas on reacting with metals (except Mn and Mg)?
Which of the following oxide(s) of iron would be obtained on prolonged reaction of iron with steam?
When a metal X is treated with cold water, it gives a basic salt Y with molecular formula XOH (Molecular mass = 40) and liberates a gas Z which easily catches fire. Identify X, Y and Z and also write the reaction involved.
Material: Copper wire, Iron nail, Beaker or Big test tube.
Chemicals: Ferrous Sulphate and Copper Sulphate Solution.
- Which reaction you will study with the help of the above material and solutions? Draw the diagram of the experiment arrangement.
- How do you identify that the reaction is carried out?
- Which type of reaction did you observe?
Metal oxides generally react with acids, but few oxides of metal also react with bases. Such metallic oxides are:
- MgO
- ZnO
- Al2O3
- Cao
Select the appropriate state symbols of the products given as X and Y in the following chemical equation by choosing the correct option from table given below:
\[\ce{Zn_{(s)} + H_2SO_{4(l)} ->ZnSO_{4(X)} + H_{2(Y)}}\]
