The number of six-membered carbon rings and five-membered carbon rings present in Buckminsterfullerene are $x$ and $y$ respectively. The sum of $x$ and $y$ is:

Consider the following reactions:
$PCl_{3} + 3H_{2}O \longrightarrow A + 3HCl$
$A + H_{2}O \longrightarrow B + HCl$
Identify the number of ionisable protons present in the product $B$.

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'.

Carborundum is obtained when silica is heated at high temperature with

Thermodynamically most stable allotrope of carbon is

$CO + NaOH \to $