Question

Which of the following reactions does not yield phosphine?
A. Hydrolysis of calcium phosphide
B. Hydrolysis of White phosphorous with `NaOH` solution
C. Heating an concentrated solution of sodium hydroxide with red phosphorus
D. Boiling `P_(4)O_(6)` with water

Answer 1

Correct Answer - 3
Unlike white phosphorus ,red phosphorus does not react with hot `NaOH` solution:
`underset("phosphorus")underset("White")(P_(4)(s))+3OH^(-) (aq.)+3H_(2)O(l) rarr PH_(3)(g)+underset("Phosphinate")(3H_(2)PO_(2)^(-) (aq.))`
Phosphine can prepared by mixing a phosphide of a very electropositive metal with water:
`Ca_(3)P_(2)(s) +6H_(2)O(l) rarr 2PH_(3)(g)+3Ca(OH)_(2)(aq.)`
Phosphine can also be obtained by heating phosphorus acid obtained by boiling `P_(4)O_(6)` with water
`P_(4)O_(6)+H_(2)O rarr H_(3)PO_(3)`
`4H_(3)PO_(3) rarr 3H_(3)PO_(4)+PH_(3)`