`NH_(4)CI +Na_(2)HPO_(4)+4Z rarr underset(("sparingly soluble salt"))(A)+ NaCI A overset(Delta)rarr A' +4Z`
`A' overset(Delta)underset("High" T)rarr X+Y uarr +Z`
Compound (Z) is a neutral oxide and turns anhydrous `CuSO_(4)` blue. Gas (Y) is a basic gas which can also be obtained by treating ammonium sulphate with lime water. sequences mentioned above involve balanced reactions.
The compound X is:

Options

A. `NaHPO_(4)`
B. `Na_(3)PO_(3)`
C. `NaPO_(3)`
D. `Na_(3)PO_(4)`

Answer

C

Explanation

`Z rarr H_(2)O, A rarr Na(NH_(4))HPO_(4).4H_(2)O, X rarr NaPO_(3)`
`Y rarr NH_(3),A' rarr Na(NH)_(4)HPO_(4)`