States of Matter - Result Question 90
90. At room temperature, ammonia gas at $1 \hspace {1mm} atm$ 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 end through which $HCl$ gas is sent in. What is the value of $p$ ?
(1982,4 M)
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Answer:
Correct Answer: 90. $(2.20 {~\hspace {1mm} atm})$
Solution:
Rate of effusion $(r) \propto \dfrac{p}{\sqrt{M}}$
$\Rightarrow \dfrac{r\left(NH _3\right)}{r(HCl)} =\dfrac{1}{\sqrt{17}} \times \dfrac{\sqrt{36.5}}{p} \Rightarrow \dfrac{40}{60} \times \dfrac{1}{p} \sqrt{\dfrac{36.5}{17}} $
$\Rightarrow p =\dfrac{3}{2} \sqrt{\dfrac{36.5}{17}}=2.20 {~\hspace {1mm} atm}$
BETA
