B\(_2\)H\(_6\), H\(_2\)O
Both BeH\(_2\) and MgH\(_2\) are known to form polymeric structures. BeH\(_2\) can adopt a linear polymeric structure due to bridging hydrogen atoms, while MgH\(_2\) forms polymeric networks in its crystal lattice.
The following graph indicates the system containing 1 mole of gas involving various steps. When it moves from Z to X, the type of undergoing process is: