$X \xrightarrow{CoCl_2} CaCl_2 + Y \uparrow$; the effective ingredient of $X$ is

Hydrolysis of which of the following carbides does not take place?

It is observed that $Pb^{2+}$ is more stable than $Pb^{4+}$, while $Sn^{2+}$ is less stable than $Sn^{4+}$. Consider the following reactions:
$PbO_{2} + Pb \rightarrow 2PbO; \Delta_{r}G^{\circ} (1)$
$SnO_{2} + Sn \rightarrow 2SnO; \Delta_{r}G^{\circ} (2)$
Identify the correct set from the following.

Identify the incorrect order against the stated property.

What do you understand by $(a)$ inert pair effect,$(b)$ allotropy,and $(c)$ catenation?

Identify the correct statement.