The number of white coloured salts, among the following is

(a) $\mathrm{SrSO}_4$

(b) $\mathrm{Mg}\left(\mathrm{NH}_4\right) \mathrm{PO}_4$

(c) $\mathrm{BaCrO}_4$

(d) $\mathrm{Mn}(\mathrm{OH})_2$

(e) $\mathrm{PbSO}_4$

(f) $\mathrm{PbCrO}_4$

(g) $\mathrm{AgBr}$

(h) $\mathrm{PbI}_2$

(i) $\mathrm{CaC}_2 \mathrm{O}_4$

(j) $\left[\mathrm{Fe}(\mathrm{OH})_2\left(\mathrm{CH}_3 \mathrm{COO}\right)\right]$

Among the following oxides of p-block elements, number of oxides having amphoteric nature is ________.

$\mathrm{Cl}_2 \mathrm{O}_7, \mathrm{CO}, \mathrm{PbO}_2, \mathrm{~N}_2 \mathrm{O}, \mathrm{NO}, \mathrm{Al}_2 \mathrm{O}_3, \mathrm{SiO}_2, \mathrm{~N}_2 \mathrm{O}_5, \mathrm{SnO}_2$

From the given list, the number of compounds with +4 oxidation state of Sulphur ________.

$$\mathrm{SO}_3, \mathrm{H}_2 \mathrm{SO}_3, \mathrm{SOCl}_2, \mathrm{SF}_4, \mathrm{BaSO}_4, \mathrm{H}_2 \mathrm{S}_2 \mathrm{O}_7 $$