Question

At which point does the white solid form? Explain why the white solid forms
at that point.

Answer 1

In the reaction between Ammonia and Hydrogen chloride.

NH3 + HCl--------> NH4Cl (dense white fumes)

The white solid or dense white fumes are formed close to the Hydrogen chloride gas or the hydrochloric acid.

This is because,  the vapour density of ammonia is lesser than that of air, making it lighter than air, hydrogen chloride is on the other hand denser than air, ammonia moves towards the hydrogen chloride by diffusion, being lighter then air while hydrogen chloride fumes, being denser, remain settled near the hydrochloric acid, hence the dense white fumes of NH4Cl which deposit forming a white solid are formed near the hydrochloric acid.

Answer 2

Answer:

A

Explanation:

It forms at point A because that is the point closest to the hydrogen chloride gas.