How will you prepare PH3 from:
(i)
Metal phosphide
(ii)
H3PO4
(iii) PСl3 and draw structure of PH3.
Answers
Answer:Calcium phosphide is mixed with water or dilutes HCl.This results in the formation of phosphine.
Ca3P2 + 6H2O → 3Ca(OH)2 + 2PH3
Ca3P2 + 6HCl → 3CaCl2 + 2PH3
In the laboratory white phosphorous is heated with concentrated sodium hydroxide solution in an inert atmosphere of CO2 to form phosphine.
P4+3NaOH+3H2O → PH3 + 3NaH2PO2
Physical and chemical properties of phosphine:
It is a colorless gas having a rotten fish smell.
It is highly poisonous gas.
PH3 is sparingly soluble in water and soluble in organic solvents.
PH3 acts as a Lewis base by donating its lone pair of electrons when it reacts with hydrogen iodide.
Under normal conditions, it is a non-combustible gas, but when heated it catches fire which results in the formation of phosphoric acid.
PH3+2O2→150CH3PO4
When it comes in contact with oxidizing agents it explodes violently.
Uses of phosphine:
In semiconductor industries, it is used in small amounts as a dopant.
PH3 is used in Holme’s signal due to its property of spontaneous combustion.
Explanation: