Question

$P{H}_3$ can be obtained by:

• A. heating hypophosphorus acid.
• B. heating orthophosphorus acid.
• C. reacting white phosphorus with hot conc,NaOH.
• D. hydrolysis of calcium phosphide.

Answer 1

Answer: (A), (B), (C), (D)

The correct options are
A heating hypophosphorus acid.
B reacting white phosphorus with hot conc,NaOH.
C heating orthophosphorus acid.
D hydrolysis of calcium phosphide.

Phosphine is produced industrially by reaction of white phosphorous with sodium/potassium hydroxide producing sodium or potassium phosphite as a byproduct.

$3KOH(hotconc.)+P_4+3H_{2}O⟶3K{H}_{2}P{O}_2+P{H}_3$

The thermal decomposition of hypophorous acid to produce phosphine is phosphorous acid. This reaction takes place at a temperature of $50℃-140℃$

$3H_{3}P{O}_2\underrightarrow{△}P{H}_3+2H_{3}P{O}_3$

Orthophosphorous acid also gives phosphine when heated

$4H_{3}P{O}_3\underrightarrow{△}⟶3H_{3}P{O}_4+P{H}_3$

Calcium phosphide when reacted with excess of water to produce calcium hydroxide and phosphine gas.

${Ca}_3{P}_2+6H_{2}O⟶3Ca{OH}_2(aq.)+2P{H}_3\left(g\right)$

Thus, all four options are correct.