Tag: electroplating and its application

Questions Related to electroplating and its application

The tarnishing of silver ornaments in atmosphere is due to:

chemistry changes - physical and chemical effects of oxidation reactions in daily life corrosion of metals electroplating and its application

  1. $Ag _{2}O$

  2. $Ag _{2}S$

  3. $Ag _{2}CO _{3}$

  4. $Ag _{2}SO _{4}$

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Correct Option: A,B
Explanation:

The tarnishing of silver ornaments in atmosphere is due to formation of silver oxide $Ag _{2}O$ and silver sulphide $Ag _{2}S$.

$2Ag\, +\, \displaystyle 
\frac{1}{2}{O _{2}}\, \rightarrow\, Ag _{2}O$

$2Ag\, +\, H _{2}S\, \rightarrow\, Ag _{2}S\, +\, H _{2}$

Hence, option A and B are correct.

Which metal is protected by a layer of its own oxide?

chemistry changes - physical and chemical effects of oxidation reactions in daily life corrosion of metals electroplating and its application

  1. $Al$

  2. $Ag$

  3. $Au$

  4. $Fe$

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Correct Option: A
Explanation:

Aluminium in air is ordinarily protected by a molecule-thin layer of its own oxide. This aluminium oxide layer serves as a protective barrier to the underlying aluminium itself and preventing chemical reactions with the metal.

Zinc corrodes in ____________________.

chemistry chemical reactions and equations effects of oxidation reactions in daily life corrosion of metals electroplating and its application

  1. 2 $M$ alkaline solution

  2. 2 $M$ acid solution

  3. 2 $M$ neutral salt solution

  4. all of the above

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Correct Option: B
Explanation:

Corrosion requires acidic medium. Hence zinc corrodes in 2 $M$ acid solution.


Hence, option B is correct.

Rusting of iron is catalysed by which of the following:

chemistry changes - physical and chemical effects of oxidation reactions in daily life corrosion of metals electroplating and its application

  1. $Fe$

  2. $Zn$

  3. O$ _{2}$

  4. $H^{+}$

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Correct Option: D
Explanation:

The rusting or iron occurs in acidic medium. Hence it is catalyzed by $ { H }^{ + } $ ions.

Hence, correct option is D.