(a) (i) `3Cl_(2) + 6NaOH to NaCl + NaCl + NaCl O_(3) + 3H_(2)O`.
(ii) Fe (III) Salt it reduced to Fe (II Salt) `2Fe^(3+) + SO_(2) + 2H_(2)O to 2Fe^(2+) + SO_(2-)^(4) + 4H^(-)`
(b) (i) It has one P= O, one P- H and two P-OH bonds. Since it has tow P-OH bonds, so it has two ionisable H atoms. Therefore, it behaves as dibasic or diprotic.
(ii) Fluorine done not paly the role of a central atom in interhalogen compounds because it is more electronegative elements and cannot exhibit any poisitive oxidation state.
(iii) Noble gases have low boiling point because atoms are held logether by weak vander waals force. Hence their boiling point is low.