$$\begin{gathered} {\mathrm{CaC}}_2+2{\mathrm{H}}_2\mathrm{O}\to \mathrm{X} \\ {\mathrm{CH}}_3-{\mathrm{CH}}_2\mathrm{Cl}\stackrel{\mathrm{alc}.\mathrm{KOH}}{\to }\mathrm{Y};\mathrm{X}\stackrel{\mathrm{Z}}{\to }\mathrm{Y}; \end{gathered}$$

In this reaction the reagent ‘z’ is

$$\begin{gathered} {\mathrm{CaC}}_2+2{\mathrm{H}}_2\mathrm{O}\to {\mathrm{C}}_2{\mathrm{H}}_2\left(\mathrm{X}\right)+\mathrm{Ca}{\left(\mathrm{OH}\right)}_2 \\ {\mathrm{CH}}_3-{\mathrm{CH}}_2\mathrm{Cl}\stackrel{\mathrm{alc}.\mathrm{KOH}}{\to }{\mathrm{CH}}_2={\mathrm{CH}}_2\left(\mathrm{Y}\right) \\ {\mathrm{C}}_2{\mathrm{H}}_2\left(\mathrm{X}\right) \stackrel{ }{ \stackrel{{\mathrm{H}}_2/\mathrm{pd} -{\mathrm{BaSO}}_4}{\to } {\mathrm{CH}}_2={\mathrm{CH}}_2} \end{gathered}$$ 

It is used for complete Hydrogenation of