(a)(i) Arrange the following elements in the order of increasing reactivity. Iron, Lead, Magnessium, Aluminium.
(ii) Which of the following elements in (a)(i) above reacts with sodium hydroxide to give hydrogen?
(b) What property of tetraoxosulphate (VI) acid does each of the following reactions illustrate?
(I) S + 2H\(_2\)SO\(_4\) —> 3SO\(_4\) + 2H\(_2\)O
(ii) MgO + H\(_2\)SO\(_4\) —> MgSO\(_4\) + H\(_2\)O
(iii) C\(_{12}\)H\(_{22}\)C\(_{11}\) + H\(_2\)SO\(_4\) —> 12C + H\(_2\)SO\(_4\) + 11H\(_2\)O
Explanation
(a) In increasing order of reactivity
(i) Lead < Iron < Aluminium < Magnesium OR Magnesium > Aluminium > Iron > Lead.
(ii) Give H\(_2\) with NaOH, Aluminium and lead
(b) H\(_2\)SO\(_4\) behaves as
(i) oxidising agent in reaction with S
(ii) typical acid (neutralisation) in reaction with MgO
(iii) dehydrating agent in reacticn with Cl\(_2\)H\(_{22}\)O\(_{11}\).