Advertisements
Advertisements
Question
Explain the following methods to protect metals from corrosion:
Galvanization
Advertisements
Solution
Galvanization:
1) The rusting of iron can be prevented by coating the metal surface with another metal such as zinc, that is oxidized in preference to iron. This process is called galvanization.
2) If the zinc layer is scratched, even then it protects iron from corrosion as long as Fe and Zn are in contact. If Fe is oxidized to Fe2+, then Zn immediately reduces Fe2+ back to Fe.
APPEARS IN
RELATED QUESTIONS
The process of leaching alumina, using sodium carbonate is called
- Bayer's process
- Decomposition
- Cyanide process
- Hall's process
What is the chemical composition of malachite?
- CuO . CuC03
- Cu(OH)2 CuC03
- CuO.Cu(OH)2
- Cu2O . Cu(OH)2
Purification of aluminium by electrolytic refining is carried out by
(a)Hoope process
(b)Hall process
(c)Baeyer process
(d)Serperck process
In the extraction of Al, impure Al2O3 is dissolved in conc. NaOH to form sodium aluminate and leaving impurities behind. What is the name of this process?
Indicate the principle behind the method used for the refining of zinc.
Name the method used for refining of copper metal.
Differentiate between “minerals” and “ores”.
Define Leaching.
Which among the following minerals does NOT contain aluminium?
(a) Cryolite
(b) Siderite
(c) China clay
(d) Corundum
Explain the following methods to protect metals from corrosion:
Passivation
Why does copper obtained in the extraction from copper pyrites have a blistered appearance?
What is the role of the following compound-
SiO2 in the extraction of copper from copper pyrites?
A current liberates 0.50 g of hydrogen in 2 hours. The weight of copper (at. wt. = 63.5) deposited at the same time by the same current through copper sulphate solution is ______.
What happens when a nickel rod is dipped into a copper sulphate solution? Justify your answer.
[\[\ce{E{^{\circ}_{Ni^{+2}/Ni}}}\] = − 0.25 V and \[\ce{E{^{\circ}_{Cu^{+2}/Cu}}}\] = +0.34 V]
Bauxite has the composition
What are the differences between minerals and ores?
Metals which occur in their native state in nature:
Which among the following statement is correct?
Which of the following options are correct?
(i) Cast iron is obtained by remelting pig iron with scrap iron and coke using hot air blast.
(ii) In extraction of silver, silver is extracted as cationic complex.
(iii) Nickel is purified by zone refining.
(iv) Zr and Ti are purified by van Arkel method.
In the thermite process, the reducing agent is:
Metal always found in Free State is
In the extraction of iron, the slag produce is
Pyrolusite is ______.
