Which one of the following oxides is neutral?

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

The name of the structure of silicates in which three oxygen atoms of $[SiO_4]^{4-}$ are shared is :-

Which of the following statements are correct?
$i$. The basic structural unit of silicates is $SiO_4^{4-}$
$ii$. Silicones are biocompatible
$iii$. Producer gas contains $CO$ and $N_2$
The correct option is

Assertion : $Pb^{4+}$ compounds are stronger oxidizing agents than $Sn^{4+}$ compounds.
Reason : The higher oxidation states for the group $14$ elements are more stable for the heavier members of the group due to 'inert pair effect'.

Which of the following compounds is formed when chlorine gas reacts with dry slaked lime $Ca(OH)_2$?