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प्रश्न
Copy and complete the following table :
| Anode | Electrolyte | |
| Purification of copper |
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उत्तर
| Anode | Electrolyte | |
| Purification of copper | Impure copper | Solution of copper sulphate and dilute sulphuric acid |
APPEARS IN
संबंधित प्रश्न
Name the following :
The process of coating of iron with zinc
Name the metallic ions that should be present in the electrolyte when an article made of copper is to be electroplated with silver.
State one relevant observation for the following:
At the anode when aqueous copper sulphate solution is electrolysed using copper electrodes.
Choose the correct answer from the options given below:
The electrolyte used for electroplating an article with silver is
A. Silver nitrate solution
B. Silver cyanide solution
C. Sodium argentocyanide solution
D. Nickel sulfate solution
How would you change Cu2+ ion to Cu?
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:
The blue colour of aqueous copper sulphate fades when it is electrolysed using platinum electrodes.
The following questions are about electroplating of copper wire with silver.
(a) What ions must be present in the electrolyte?
(b) Of what substance must the anode be made up of?
(c) What will the cathode be made up of?
(d) Write the equation for the reaction which takes place at the cathode.
Mr Ramu wants electrolyte his key chain with nickel to prevent rusting. For this electroplating
(i) Name the electrolyte
(ii) Name the cathode
(iii) Name the anode
(iv) Give the reaction at the cathode
(v) Give the reaction at the anode
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.
-
- A diagram of the apparatus used for step 1 is shown
- 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? - Explain why the concentration of copper ions in the electrolyte remains constant throughout step 1.
- The chemical process taking place on the surface of the object is \[\ce{Cu^2+(aq) + 2e- ->Cu(s)}\]
- A diagram of the apparatus used for step 1 is shown
- Give two changes which would be needed in order to coat nickel on to the object in step 2.
- Write down the reaction taking place at the positive electrode during step 3.
