Question

Phosphine is generally prepared in the laboratory:

• A. By heating phosphorus in a current of hydrogen
• B. By heating white phosphorus with an aqueous solution of caustic potash
• C. By decomposition of \( P_2H_4 \) at 110°C
• D. By heating red phosphorus with an aqueous solution of caustic soda

Hint:

Phosphine is commonly prepared in the laboratory using caustic potash and white phosphorus under controlled conditions.

Answer 1

The Correct Option is B

Phosphine (\( PH_3 \)) is generally prepared by heating white phosphorus with an aqueous solution of caustic potash. This process produces phosphine gas.
Final Answer: \[ \boxed{\text{By heating white phosphorus with an aqueous solution of caustic potash}} \]