The P Block Elements - Result Question 19
####19. Which one of the following substance is used in the laboratory for fast drying of neutral gases?
[1992]
(a) Phosphorus pentoxide
(b) Active charcoal
(c) Anhydrous calcium chloride
(d) $Na_3 PO_4$.
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Solution:
- (a) Phosphorus pentoxide has great affinity for water. It forms ortho phosphoric acid on absorbing water
$ \text{ i.e. } P_4 O _{10}+6 H_2 O \longrightarrow 4 H_3 PO_4 $
It is thus used as a powerful dehydrating or drying agent.
