Question

Two gases, ammonia and hydrogen chloride, are passed in a long glass tube from opposite ends. The white ring will be formed at:

• A. nearer to $HCl$ end
• B. nearer to ammonia end
• C. throughout the length of tube
• D. at the centre of the tube.

Answer 1

Answer: (A)

nearer to $HCl$ end

Answer 2

Molecular w.t. of $N{{H}_{3}}=14+3=17$ Molecular w.t. of $HCl=35.5+1=36.5$ According to Grahams law: $r\propto \frac{1}{\sqrt{M}}$ Hence, the rate of diffusion will be higher for ammonia as it is lighter than $HCl.$ Hence, white ring of $N{{H}_{4}}Cl$ will be formed nearer to $HCl$ end.