Chemistry
A metal article is to be electroplated with silver. The electrolyte selected is sodium argentocyanide.
(i) What kind of salt is sodium argentocyanide.
(ii) Why is it preferred to silver nitrate as an electrolyte?
(iii) State one condition to ensure that the deposit is smooth, firm and long lasting.
(iv) Write the reaction taking place at the cathode.
(v) Write the reaction taking place at the anode.
Electrolysis
53 Likes
Answer
(i) It is a Complex Salt.
(ii) Migration of Ag1+ ions from above complex salt soln. is slow compared to that from silver nitrate. Hence, an even deposition of metal silver is obtained on the article. Therefore, the electrolyte sodium argentocyanide soln. is preferred over silver nitrate solution.
(iii) A low current for a longer time should be used to ensure that the deposit is smooth, firm and long lasting.
(iv) Ag1+ + 1e- ⟶ Ag [deposited]
(v) Ag - 1e- ⟶ Ag1+ [Anode diminishes in mass]
Answered By
30 Likes
Related Questions
Aqueous solution of nickel sulphate contains Ni2+ and SO42- ions
(i) Which ion moves towards the cathode?
(ii) What is the product at the anode?
Select the correct answer — The aqueous solution of the compound which contains both ions and molecules is:
- Sulphuric acid
- Hydrochloric acid
- Nitric acid
- Acetic acid
Correct the following statements — Lead bromide conducts electricity.
Select the correct answer — A compound which during electrolysis in it's molten state liberates a reddish brown gas at the anode :
- Sodium chloride
- Copper (II) oxide
- Copper (II) sulphate
- Lead (II) bromide