Number of oxygen atoms present in the chemical formula of fuming sulphuric acid is . . . . .

In the following reaction,identify the nature of the product formed by the complete hydrolysis of the underlined atom at $R.T.$:
$H_2\underset{-}{S}_2O_7 + H_2O \longrightarrow 2H_2SO_4$

Which of the following is a mixed oxide?

The bleaching action of bleaching powder is due to the liberation of

$SiCl_4$ on hydrolysis forms '$X$' and $HCl$. Compound '$X$' loses water at $1000^{\circ} C$ and gives '$Y$'. Compounds '$X$' and '$Y$' respectively are:

Among the following oxides of $p$-block elements,the number of oxides having amphoteric nature is: $Cl_2O_7, CO, PbO_2, N_2O, NO, Al_2O_3, SiO_2, N_2O_5, SnO_2$