Answer to Question #101523 in Physical Chemistry for Mrinal

Question

Two flasks A and B of equal volume containing NH3 and HCl gases are connected by a narrow tube of negligible volume. The two gases were prevented from mixing by stopper fitted in connecting tube. For further detail of experiment refer to the given figure. What will be the final pressure in each flask when passage connecting the two tubes are opened. Assume ideal gas behaviour of NH3 and HCl gases and the reaction
NH3 + HCl ----> NH4Cl is quantitative

Answer 1

Answer: Ammonium chloride is a white solid, hence theoretically pressure will be zero.

NH3(g) + HCl(g) ----> NH4Cl(s)

Reaction of two gaseous molecule form solid substance, hence pressure reduces as solid substance does not imply force on container surface.