(i) Name the method used to extract metals of high reactivity. (ii) Name the main ore of mercury. How is mercury obtained from its ore ? Give balanced chemical equations. (iii) Explain what is thermite reactions with the help of balanced equation. How is it used join railway tracks or cracked machine parts ?

(i) Name the method used to extract metals of high reactivity. (ii) N

1.	(i) Name the method used to extract metals of high reactivity. (ii) Name the main ore of mercury. How is mercury obtained from its ore ? Give balanced chemical equations. (iii) Explain what is thermite reactions with the help of balanced equation. How is it used join railway tracks or cracked machine parts ?
Answer» Solution :(a) Electrolytic reduction. (B) Cinnabar (HGS) By roasting and then self reduction `2HgS + 3O_(2) overset("Heat")rarr 2HgO + 2SO_(2)` `2HgO overset("Heat")rarr2Hg + O_(2)` (c ) Reaction of `Fe_(2)O_(3)` with Al is used to join railway tracks and machine PARTS as it is exotermic. This reaction is known as thermite reaction. `Fe_(2)O_(3) + 2Al rarr 2Fe + Al_(2)O_(3) + "Heat"` The amount of heat evolved is so large that the metal (Fe) is produced in the molten STATE.