Question 8 :
Which one of the methods given in column- I is applied for the extraction of the metal given in column II:<br/><blockquote><table class="wysiwyg-table"> <tbody><tr> <td><b>Column -I</b></td> <td><b>Column - II</b></td> </tr> <tr> <td>(A)&#160;Electrolytic reduction</td> <td>(i)&#160;Aluminium</td> </tr> <tr> <td>(B) Reduction with carbon</td> <td>(ii)&#160;Zinc</td> </tr> <tr> <td>(C) Reduction with aluminium</td> <td>(iii)&#160;Sodium</td> </tr> <tr> <td>&#160;</td> <td>(iv)&#160;Iron</td> </tr> <tr> <td>&#160;</td> <td>(v)&#160;Manganese</td> </tr> <tr> <td>&#160;</td> <td>(vi)&#160;Chromium</td> </tr></tbody></table></blockquote>

Question 13 :
Metals which loses electrons more easily than hydrogen are more reactive than $H_2$ and they can&#160;:

Question 14 :
During the formation of Ionic compound $CaO$, the transfer of electron is from $X$ orbital to $Y$ orbital. Then $X$ and $Y$ are respectively:

Question 15 :
The order of reactivity of $K, Mg, Au$ and $Zn$ with water is:

Question 17 :
Partial roasting of sulfide ore is done in the metallurgy of copper called ____________.<br/>

Question 21 :
Assertion (A): In the electrolysis of aqueous NaCl,Na is preferentially discharged at the mercurycathode forming sodium amalgam.<br>Reason (R) : It is due to the fact that hydrogenhas a high over voltage at mercury cathode.<br>

Question 22 :
Consider the following statements. Roasting is carried out to:<br/>(i) convert sulphide to oxide and sulphate.<br/>(ii) to remove impurities of $CuS$ and $FeS$ present in the ore of tin stone $(SnO_2)$ as $CuSO_4$ and $FeSO_4$.<br/>(iii) melt the ore.<br/>(iv) remove arsenic and sulphur impurities.<br/>Of these statements:<br/>