Question

At room temperature, ammonia gas at 1 atm pressure and hydrogen chloride gas at p atm pressure are allowed to effuse through identical pin holes from opposite ends of a glass tube of one metre length and of uniform cross-section. Ammonium chloride is first formed at a distance of 60 cm from the and through which HCI gas rs sent in. What is the value of p ?

Answer 1

Pressure of ammonia = 1 atm

Pressure of HCI - p atm

The length of glass tube = 1m = 100 cm

The distance of HCI from the end = 60 cm 

(As NH₄CI is formed at 60 cm from the end through which HCI gas is sent)

Thus, the distance of NH₃ from other end

= 100 - 60 = 40 cm

According to Graham's law