A-Level Chemistry Question Analysis Topic: Chemistry - Short Questions
Exam Questions:
1) What is the role of zinc metal in the extraction of silver?
2) Write the name of monomers used for getting the following polymers:
(i) Bakelite (ii) Neoprene
Answers:
For A-Level Chemistry, you should know:
1) The finely powdered silver ore is treated with dilute KCN solution during the silver extraction process to create a cyano complex of silver. This complex is soluble in water.
The solution is then given zinc. Silver is displaced by more electropositive zinc in the complex.
The following are the equations for the respective statements above:
Ag2S + 4NaCN ⇌ 2Na[Ag(CN)2] + Na2S
2Na[Ag(CN)2] + Zn → Na2[Zn(CN)4] + 2Ag ↓
2) (i) Bakelite is essentially a phenol-formaldehyde polymer. Phenol and formaldehyde are the monomers that are used in production.
(ii) Chloroprene (2-chlorobuta-1,3-diene) is polymerized to create neoprene.
Work hard for your A-Level Chemistry examination!
End of analysis. Great!
