$2.0 \mathrm{~g}$ of activated charcoal is added to $100 \mathrm{~mL}$ of $0.5 \mathrm{M}$ acetic acid…
$2.0 \mathrm{~g}$ of activated charcoal is added to $100 \mathrm{~mL}$ of $0.5 \mathrm{M}$ acetic acid (molar mass $60 \mathrm{~g} \mathrm{~mol}^{-1}$ ), shaken well and filtered. The concentration of solution is reduced to $0.4 \mathrm{M}$. How many grams of acetic acid is adsorbed on charcoal per gram?
0.1
0.2
0.3
0.15
Solution
Change in concentration $=0.5-0.4=0.1 \mathrm{M}$
$\Rightarrow$ Change in moles of acetic acid $=0.1 \times 0.1$
$\begin{aligned} &=0.01 \mathrm{~mol} . \\ & \Rightarrow \text { Mass absorbed }=0.01 \times 60=0.6 \mathrm{~g} .\end{aligned}$
$\Rightarrow$ Mass absorbed per gram of charcoal $=\frac{0.6}{} \quad 0.3 \mathrm{~g}$