Determine the number of degrees of freedom for

$($i$)$ the system prepared by the decomposition of $CaC{O}_3$ into an evacuated space by the reaction

$CaC{O}_3(s)longrightarrowCaO(s)+C{O}_2(g)$

$($ii$)$ A system of two non$-$reacting species which exists as azeotrope in vapour liquid equilibrium