Advertisements
Advertisements
प्रश्न
Describe what happens to the iron object and the copper rod.
Advertisements
उत्तर
The copper anode continuously dissolves as ions in solution and is replaced periodically. The electrolyte dissociates into Cu2+ ions, which migrate towards the iron object taken as the cathode and are deposited as neutral copper atoms on the cathode.
Electrolyte: Aqueous solution of nickel sulphate
Dissociation: \[\ce{CuSO4 ⇌ Cu^2^+ + SO^2^-4}\]
\[\ce{H2O ⇌ H^+ + OH^-}\]
Electrodes:
- Cathode: Article to be electroplated
- Anode: Block of pure copper
Electrode reactions:
- Reaction at cathode: \[\ce{Cu^{2+} + 2e^- -> Cu}\] (deposited)
- Reaction at anode: \[\ce{Cu - 2e^- -> Cu^{2+}}\]
संबंधित प्रश्न
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.
State the electrode reaction at the anode during electrolysis of:
Aqueous copper sulphate solution.
Give reason for the following:
The blue colour of aqueous copper sulphate fades when it is electrolysed using platinum electrodes.
Give reason for the following:
For electroplating with silver, silver nitrate is not used as an electrolyte.
Explain the term:
Electro refining
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).
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.
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
