Extraction depends on reactivity

This type of question, asked 4 times: 2023, 2024, 2025, 2026. All 9 questions below, oldest first.

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Question 1 (case study, 4 parts)
2023
Metals are required for a variety of purposes. For this we need their extraction from their ores. Ores mined from the earth are usually contaminated with many impurities which must be removed prior to the extraction of metals. The extraction of pure metal involves the following steps : (1) Concentration of ore (2) Extraction of the metal from the concentrated ore (3) Refining of the metal
37 (a) $Name an ore of Mercury and state the form in which Mercury is present in it.$
37 (b) $What happens to zinc carbonate when it is heated strongly in a limited supply of air ?$
37 (c) $\mathrm{Fe_2O_3}$
37 (c) OR $We cannot use carbon to obtain sodium from sodium oxide. Why ? State the reactions taking place at cathode and anode during electrolytic reduction of sodium chloride.$
Question 2 (case study, 4 parts)
2023
On the basis of reactivity metals are grouped into three categories – (i) Metals of low reactivity (ii) Metals of medium reactivity (iii) Metals of high reactivity Therefore metals are extracted in pure form from their ores on the basis of their chemical properties. Metals of high reactivity are extracted from their ores by electrolysis of the molten ore. Metals of low reactivity are extracted from their sulphide ores, which are converted into their oxides. The oxides of these metals are reduced to metals by simple heating.
37 (a) $Name the process of reduction used for a metal that gives vigorous reaction with air and water both.$
37 (b) $Carbon cannot be used as a reducing agent to obtain aluminium from its oxide ? Why ?$
37 (c) $Describe briefly the method to obtain mercury from cinnabar. Write the chemical equation for the reactions involved in the process.$
37 (c) OR $Differentiate between roasting and calcination giving chemical equation for each.$
Question 3
2024
28 (a) $State giving reason the reduction process to obtain the following metals from their compounds : (i) Mercury, (ii) Copper and (iii) Sodium$
Question 4
2025
Two statements are given, one labelled Assertion (A) and the other labelled Reason (R). Select the correct answer from the options given below.
17 $Assertion (A) : The metals high up in the reactivity series cannot be obtained from their compounds by heating with carbon. Reason (R) : Displacement reactions can also be used to obtain metal.$
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Question 5
2025
27 $(a) “Displacement reactions also play a key role in extracting metals in the middle of the reactivity series.” Justify this statement with two examples. (b) Why can metals high up in the reactivity series not be obtained by reduction of their oxides by carbon ?$
Question 6
2025
6 $The metals obtained from their molten chlorides by the process of electrolytic reduction are :$
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Question 7
2025
3 $The most common method of extraction of metals from their oxide ores is :$
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Question 8 (case study, 4 parts)
2026
Most of metals occur in combined state in form of ores. Carbonate ores are converted into oxides by calcination and sulphide ores by roasting. Oxides are reduced with suitable reducing agent like carbon to get free metal. Highly reactive metals like – Al, Mg are also used as reducing agents to obtain metal from their oxides. Most reactive metals are obtained by electrolytic reduction of their molten ores. Alloying is a very good method of improving the properties of a metal. We can get desired properties by this method. The electrical conductivity and melting point of an alloy is less than that of pure metals.
28 (a) $Why carbonate or sulphide ores are converted to oxides before extraction of metal from it ?$
28 (b) $Write a reaction in which Aluminium is used as a reducing agent to obtain metal from its oxide.$
28 (c) (i) $(\mathrm{Cu_2S})$
28 (c) (ii) $(I) Why highly reactive metals cannot be obtained from their oxides by using carbon as a reducing agent ? (II) Why solder, an alloy of lead and tin, is used for welding electrical wires together ?$
Question 9
2026
26 (b) $Give reasons : (i) Metal sulphides and carbonates should be converted to their metal oxides in the process of extraction of metals. (ii) Aluminium oxide is considered as an amphoteric oxide. (iii) Metals like Na, K, Ca and Mg are never found in their free state in nature.$

Extraction depends on reactivity

Question 1 (case study, 4 parts)

Question 2 (case study, 4 parts)

Question 3

Question 4

Question 5

Question 6

Question 7

Question 8 (case study, 4 parts)

Question 9