Answer:
Point - C
Step-by-step explanation:
Ethylamine has a molar mass = 45.08 g/mol
While, HBr has molar mass = 80.91 g/mol
This means ethylamine will travel more distance than HBr in given time.
So, the white solid (Ethylammonium bromide) will form at point C.
Why Point C?
Point C is the only point which is farthest from ethylamine and closest to HBr. This point depicts that ethylamine has travelled more distance than HBr.