Question

A waxy transluscent solid, M, insoluble in water but soluble in CS₂ glows in dark. M dissolves in NaOH in an inert atmosphere giving a poisonous gas (N). Also M catches re to give dense white fumes of Q.
(a) Identify M, N and Q and write the chemical equations of the reactions
involved.
(b) ‘M’ exists in the form of discrete tetrahedral molecules. Draw its
structure.
(c) ‘M’ on heating at 573K is changed into other less reactive form, R,
which is non-poisonous, insoluble in water as well as in CS₂ and does
not glow in dark. Identify R and draw its structure.

Answer 1

[Hint :  (a) M is white phosphorus.
P₄ + 3NaOH + 3H₂O  → PH₃ + 3NaH₂PO₂ (N)

P₄ + 5O₂→  P₄O₁₀

                                     white fumes (Q)