(a) Number of ions that are regarded as ionic carbides amongst

$\left({\mathrm{C}}^{4-}, {\mathrm{C}}_2^{2-}, {\mathrm{C}}_3^{4-}, {\mathrm{C}}_4^{3-}\right)=X$

(b) When oxalic acid is heated with cone. ${\mathrm{H}}_2\mathrm{S}{0}_4$it produces a number of different gases amongst

$\left(\mathrm{CO},{ \mathrm{CO}}_2,{ \mathrm{SO}}_3\right)=Y$

(c) Number of molecules having a V-shaped structure amongst

$\left({\mathrm{SnCl}}_2,{ \mathrm{PbCl}}_2, \mathrm{COS}\right)=Z$

Find X + Y +Z

With fewer electronegative elements, carbon can create three different types of carbides: ionic carbides, which contain metal cations and ${\mathrm{C}}^{4-}$(methide) or ${ \mathrm{C}}_2^{2-}$ (acetylide) anions; interstitial carbides; and covalent carbides. Only 3 ionic carbides are provided here.
Oxalic acid is heated in the presence of concentrated sulfuric acid, which results in the production of carbon monoxide, carbon dioxide, and a water molecule.
Because a single pair of electrons are present, the geometry of ${\mathrm{SnCl}}_2$ and ${\mathrm{PbCl}}_2$is V-shaped.

Thus,

$X=3,Y=2, Z=2$

So,

$=\mathrm{X}+\mathrm{Y}+\mathrm{Z}$

$$\begin{gathered} =3+2+2 \\ =7 \end{gathered}$$