Question

The particles of hydrochloric acid have a greater mass than the particles of ammonia.suggest why the ammonia chloride is formed nearer to the hydrochloric acid end of the tube than the ammonia solution end

Answer 1

So diffusion is inversely proportional to Mass.

Since Ammonia molecules have a lesser atomic mass, they diffuse faster than HCl molecules.

Hence Ammonia Molecules travel faster, so in the same time, Ammonia molecules cover a greater distance than HCl molecules.