$$ \text { Match the following. } $$

$$ \begin{array}{llll} \hline & \text { Ores } & & \text { Composition } \\ \hline \text { A. } & \text { Calamine } & \text { (i) } & \mathrm{CuFeS}_2 \\ \hline \text { B. } & \text { Chalcopyrite } & \text { (ii) } & \mathrm{ZnCO}_3 \\ \hline \text { C. } & \text { Bauxite } & \text { (iii) } & \mathrm{Fe}_2 \mathrm{O}_3 \\ \hline \text { D. } & \text { Haematite } & \text { (iv) } & \mathrm{Al}_2 \mathrm{O}_3 \cdot 2 \mathrm{H}_2 \mathrm{O} \\ \hline \end{array} $$

$$ \text { The correct match is } $$

The molecular formula of metaphosphoric acid is

The final acid product obtained during the synthesis of $\mathrm{H}_2 \mathrm{SO}_4$ by contact process is

Among the following series of transition metal ions, the one in which all the metal ions have $3 d^2, 3 p^6$ electronic configuration is

(Atomic number, $\mathrm{Ti}=22, \mathrm{~V}=23, \mathrm{Cr}=24$, $\mathrm{Mn}=25$ )