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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 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.
How would you change Cu2+ ion to Cu?
Give three applications of electrolysis.
How is impure copper purified by electrolysis ? Explain.
The following question relate to the electroplating of an article with silver.
What ions must be present in the electrolyte?
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.
Element X is a metal with valency 2. Element Y is a non-metal with valency 3.
(a) Write equations to show how X and Y form ions.
(b) If Y is diatomic gas, write the equation for the direct combination of X and Y to form a compound.
(c) Write two applications of electrolysis in which anode diminish in mass.
(d) If the compound formed between X and Y is melted and an electric current passed through the molten compound, the element X will be obtained at the _____ and the Y at the ________of the electrolytic cell. (Provide the missing words).
Write two applications of electrolysis in which the anode diminishes in mass.
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.
