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प्रश्न
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.
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- 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.
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उत्तर
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- reddish brown deposit/pink deposit/mass increases
- As anode released Copper ions the concentration of copper ions does not decrease
- The anode should be made up of Nickel and the electrolyte should be aq. Nickel sulphate or any salt solution of Nickel
- \[\ce{Ag -> Ag+ + e-}\]
APPEARS IN
संबंधित प्रश्न
Out of Cu and Ag, which is more active?
Give reason for the following:
The blue colour of aqueous copper sulphate fades when it is electrolysed using platinum electrodes.
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).
Draw a labelled diagram to show how iron is electroplated with copper.
Describe what happens to the iron object and the copper rod.
What ions must be present in a solution used for electroplating a particular metal?
