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प्रश्न
How would you change Cu2+ ion to Cu?
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उत्तर
By supplying two electrons to Cu2+ or by loss of 2 electrons.
\[\ce{Cu^2+ + 2e- -> Cu}\]
संबंधित प्रश्न
Identify the substance underlined, in the following case
The electrolyte used for electroplating an article with silver.
State one relevant observation for the following:
At the anode when aqueous copper sulphate solution is electrolysed using copper electrodes.
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.
State the electrode reaction at the anode during electrolysis of:
Aqueous copper sulphate solution.
The following question relate to the electroplating of an article with silver.
What ions must be present in the electrolyte?
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).
The electrolyte used for electroplating an article with silver is ______.
Which solution is preferred as electrolyte, CuSO4 or FeSO4?
What ions must be present in a solution used for electroplating a particular metal?
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.
