How is phosphine prepard using the following reagents ?
(a) `HCl`
(b) `H_(2)SO_(4)`
(c ) Caustic soda

Explanation

(a) Calcium phosphide is mixed with dilute HCl. This results in the formation of phosphine.
`{:(Ca_(3)P_(2)+6HCl to3CaCl_(2)+2PH_(3)),(" ""Calcium" " ""Calcium"" ""Phosphine"),(" ""Phosphide"" ""chloride"):}`
(b) Aluminium phosphide is decomposed with dilute sulphuric acid.
`{:(2AlP+3H_(2)SO_(4)to2PH_(3)+Al_(2)(SO_(4))_(3)),("Aluminium"" ""Phosphine"" ""Aluminium"),("phosphide" " ""sulphate"):}`
(c) In the laboratory, phosphine is prepared by heating white phosphrus with concentrated NaOH solution in an inert atmosphere of `CO_(2).`
`P_(4)+3NaOH+3H_(2)Oto underset("Phosphine")(PH_(3))+underset("Sodium hypophosphite")(3NaH_(2)PO_(2))`