Question

100 ml of PH3 on heating forms P and H2. The volume change in the reaction is.
(a) An increase of 50 ml
(b) An increases of 100 ml
(c) An increase of 150 ml
(d) a decrease of 50 ml​

Answer 1

Answer:

The equation for the decomposition is:

4PH3 (g) = P4 (s)+ 6H2 (g) (Elemental phosphorus exists as tetraatomic molecules).

When the temperature and pressure remain the same, 4 ml of PH3 will give 6 ml of H2. (On applying Gay-Lussac's law ).

Hence, 100 ml of PH3 will yield 150 ml of H2.

Increase in volume = (150-100) ml = 50 ml. (The volume of solid phosphorus is negligible).

There is a 50% increase in volume.

________________________

Hope it helps U