Fertiliser Technology - Engineering

Q1:

Both white phosphorous as well as red phosphorous

A are soluble in CS2.

B burns when heated in air.

C reacts with hot caustic soda solution to give phosphine.

D all (a), (b), and (c).

ANS:B - burns when heated in air.

Both white phosphorus and red phosphorus exhibit the following characteristics:

  1. Solubility in CS2 (Carbon disulfide): Both white phosphorus and red phosphorus are soluble in CS2. This solubility is a characteristic property of phosphorus compounds.
  2. Burning when Heated in Air: Both white phosphorus and red phosphorus are pyrophoric, meaning they spontaneously ignite in air when heated to a sufficiently high temperature. This property is due to their reactivity with oxygen in the air, resulting in combustion.
  3. Reaction with Hot Caustic Soda Solution to Give Phosphine: Both white phosphorus and red phosphorus react with hot caustic soda solution (sodium hydroxide, NaOH) to produce phosphine gas (PH3) as a by-product. This reaction is a classic laboratory method for the preparation of phosphine.
So, the correct option is: All (a), (b), and (c).