English

Give reason for the following: The blue colour of aqueous copper sulphate fades when it is electrolysed using platinum electrodes.

Advertisements
Advertisements

Question

Give reason for the following:

The blue colour of aqueous copper sulphate fades when it is electrolysed using platinum electrodes.

Short/Brief Note
Advertisements

Solution

The blue colour of copper ions fades due to the decrease in Cu+2 ions, and finally, the solution becomes colourless as soon as the Cu+2 ions are finished.

shaalaa.com
  Is there an error in this question or solution?
Chapter 6: Electrolysis - lntext Questions [Page 120]

APPEARS IN

S.P. Singh Concise Chemistry [English] Class 10 ICSE
Chapter 6 Electrolysis
lntext Questions | Q 10. (a) | Page 120

RELATED QUESTIONS

Give reasons why In the electroplating of an article with silver, the electrolyte sodium argentocyanide solution is preferred over silver nitrate solution.


Copy and complete the following table:

  Anode Electrolyte
Purification of copper    

Give one word or phrase for the following:

Electrolytic deposition of a superior metal on a baser metal.


An electrolytic cell is set up using two platinum electrodes and an aqueous solution of copper (II) sulphate,
(a)draw a labelled diagram of the electrolytic cell,
(b)Name the ions present in the cell,
(c)Name the ions migrating towards the anode,
(d)Name the ions migrating towards the cathode,
(e)Name the ions which will not be discharged at electrodes during electrolysis,
(f)Write the reaction at the cathode,
(g)Write the reaction at the anode,
(h)Name the spectator ion in the solution.


Give reason for the following:

For electroplating with silver, silver nitrate is not used as an electrolyte.


The following question relate to the electroplating of an article with silver.
What ions must be present in the electrolyte?


The following question relate to the electroplating of an article with silver.
 What should be the nature of the anode?


What ions must be present in a solution used for electroplating a particular metal?


A solution of silver nitrate is a good electrolyte but is not used for electroplating an article with silver.


Electroplating steel objects with silver involves a three-step process.

Step 1: A coating of copper is applied to the object.

Step 2: A coating of nickel is applied to the object.

Step 3: The coating of silver is applied to the object.

    1. A diagram of the apparatus used for step 1 is shown

      1. The chemical process taking place on the surface of the object is \[\ce{Cu^2+(aq) + 2e- ->Cu(s)}\]
        What is the observation seen on the surface of the object?
      2. Explain why the concentration of copper ions in the electrolyte remains constant throughout step 1.
  1. Give two changes which would be needed in order to coat nickel on to the object in step 2.
  2. Write down the reaction taking place at the positive electrode during step 3.

Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×