Question

Phosphine is prepared from which of the following methods?

(a) By reacting calcium phosphide with water or dilute HCl

(b) By directly reacting phosphorous with hydrogen

(c) By passing dry chlorine over P2H4

(d) Heating while phosphorous with halides

I had been asked this question during an internship interview.

My question is from P-Block Elements topic in section P-Block Elements of Chemistry – Class 12

Answer 1

The correct choice is (a) By reacting calcium phosphide with water or dilute HCl

To elaborate: Phosphine is prepared by the reaction of calcium phosphide with water or dilute HCl.

With water: Ca3P2 + 6H2O → 2PH3 + 3Ca(OH) 2

With dilute HCl: Ca3P2 + 6HCl → 2PH3 + 3CaCl2.