For Freundlich adsorption isotherm, a plot of
log (x/m) (y-axis) and log p (x-axis) gives a
straight line. The intercept and slope for the
line is 0.4771 and 2, respectively. The mass of
gas, adsorbed per gram of adsorbent if the
initial pressure is 0.04 atm, is ______ $\times$ 10–4 g.
(log 3 = 0.4771)
Answer (integer)
48
Solution
According to Freundlich adsorption isotherm, in the median range of pressure
<br><br> ${x \over m} \propto {P^{{1 \over n}}}$
<br><br>$\Rightarrow$ ${x \over m}$ = kP$^{{1 \over n}}$
<br><br>taking log both sides, we get,
<br><br>log${x \over m}$ = logk + ${1 \over n}$ logP
<br><br>Here in graph between log${x \over m}$ and logP, slope is ${1 \over n}$ and intercepts = log k.
<br><br>$\therefore$ ${1 \over n}$ = 2 $\Rightarrow$ n = ${1 \over 2}$
<br><br>and log k = 0.4771 = log 3
<br><br>$\Rightarrow$ k = 3
<br><br>$\therefore$ ${x \over m}$ = 3P$^{{2}}$
<br><br>So, mass of gas adsorbed per gram of adsorbent
<br><br>= 3 $\times$ (0.04)<sup>2</sup>
<br><br>= 48 $\times$ 10<sup>–4</sup>
About this question
Subject: Chemistry · Chapter: Surface Chemistry · Topic: Adsorption
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