Tag: chemical effects of electric current

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Questions Related to chemical effects of electric current

Multiple choice physics chemical effects of electric current applications of electrolysis electroplating extraction of metals by electrolysis

To protect iron from corrosion and rusting , it is electroplated with 

  1. Zinc

  2. Chromium

  3. Nickel

  4. Aluminum
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Iron is coated with a more active metal like Zinc. This is a sacrificial method. If the rusting conditions are met, zinc rusts before iron and prevents iron from rusting. Zinc makes a protective layer with Zn(OH)2 and ZnCO3

Multiple choice chemistry chemical effects of electric current applications of electrolysis electroplating extraction of metals by electrolysis

The process of depositing a thin layer of desired metal over another metal by passing an electric current through some electrolyte is called :

  1. electric shielding

  2. electric polishing

  3. electric coating

  4. electroplating
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Electroplating is the application of electrolytic cells in which a thin layer of metal is deposited onto an electrically conductive surface.


Hence, option D is correct.

Multiple choice physics chemical effects of electric current applications of electrolysis electroplating extraction of metals by electrolysis

Electroplating does not help

  1. fine finish to the surface

  2. shining appearance

  3. metals to become hard

  4. protect metals against corrosion
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Electroplating is primarily used to change the surface properties of an object like appearance, corrosion protection, lubricity etc.  Thus, electroplating does not help in making the metals become hard. 

Multiple choice physics chemical effects of electric current applications of electrolysis electroplating extraction of metals by electrolysis

Chromiumhas a shiny appearance and lt does not corrode

  1. True

  2. False

  3. Ambiguous

  4. Data insufficient
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Answer is A.
Electroplating is a very useful process. It is widely used in industry for coating metal objects with a thin layer of a different metal. The layer of metal deposited has some desired property, which the metal of the object lacks. For example, chromium plating is done on many objects such as car parts, bath taps, kitchen gas burners, bicycle handlebars, wheel rims and many others.
Chromium has a shiny appearance. It does not corrode. It resists scratches. However, chromium is expensive and it may not be economical to make the whole object out of chromium. So the object is made from a cheaper metal and only a coating of chromium over it is deposited.
Hence, electroplating of chromium is done on objects like water taps and cycle bell to give them a shiny appearance and prevent them from corrosion. The statement is true.

Multiple choice physics chemical effects of electric current applications of electrolysis electroplating extraction of metals by electrolysis

In electroplating of the silver spoon with gold, the silver spoon is cleaned with a dilute acid solution to remove the  _________  from its surface.

  1. oxide layer

  2. chloride layer

  3. silver layer

  4. gold layer
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The silver spoon is cleaned with a dilute acid solution to remove the oxide layer from its surface and washed in running water until it is free from the acid.