(i) Which method will be used to convert each of them to their respective metal oxides? (a) Carbonate ore (b) Sulphide ore. (ii) Write a chemical reaction to illustrate the use of aluminium for joining cracked railway tracks. (iii) During extraction of metals, electrolytic refining is used to obtain pure metals. Which material will be used as anode and cathode for the refining of copper metal by this process?
Occurrence and extraction of metals
High importanceUsually 3 marks a paper · mostly case-based questions and short answers · asked in 3 of the last papers
Notes are being written
The board questions below are real and complete — they come from the CBSE papers themselves. The written notes for this topic are still being prepared.
Board questions on this topic
7 from the CBSE papers we hold — the exact wording the board used.
(i) Write all the reactions involved in the extraction of Zn from ZnS. (ii) Hydrogen gas is not evolved when most of the metals react with nitric acid. Give reason.
(a) "Displacement reactions also play a key role in extracting metals in the middle of the reactivity series." Justify this statement with two examples. (b) Why can metals high up in the reactivity series not be obtained by reduction of their oxides by carbon ?
The metals obtained from their molten chlorides by the process of electrolytic reduction are :
- (a) Gold and silver
- (b) Calcium and magnesium
- (c) Aluminium and silver
- (d) Sodium and iron
The metals produced by various reduction processes are not very pure; the most widely used method for refining impure metals is electrolytic refining.
What is the cathode and anode made of in the refining of copper by this process?
electrolytic refining of impure copper.
Name the solution used in the above process and write its formula.
electrolytic refining of impure copper.
How copper gets refined when electric current is passed in the electrolytic cell?