(i) Which phosphorous is heated with `CaO` to get calcium phosphide, which is then hydrolysed to get phosphine gas.
`15 CaO + 4 P_4 overset (Delta) rarr 5 Ca_3 P_2 + 3 P_2 O_5 uarr`
`Ca_3 P_2 + 6 H_2 O rarr 3 Ca(OH)_2 + 2 PH_3 uarr`
(ii) `2 NH_3 + CO_2 + H_2 O rarr (NH_4)_2 CO_3`
`CaSO_4 + (NH_4)_2 CO_3 rarr CaCO_3 darr + (NH_4)_2 SO_4`.