$100 \mathrm{mL} \mathrm{of} 0.3\mathrm{M}$ acetic acid is shaken with $0.8 \mathrm{g}$ wood charcoal. The final concentration of acetic acid in the solution after adsorption is $0.125\mathrm{M}$. The mass of acetic acid adsorbed per gram of charcoal is:

Initial moles of ${\mathrm{CH}}_3\text{ COOH }=100\times 0.3=30\text{ mile moles }$

Final moles of ${\mathrm{CH}}_3\text{ COOH }$$=100\times 0.125=12.5\text{ milimoles }$

Absorbed moles of ${\mathrm{CH}}_3\text{ COOH }$$=30-12.5=17.5\text{ mili moles }$

W.t of ${\mathrm{CH}}_3\text{ COOH }$absorbed $=17.5\times 60=1050\mathrm{mg}$

$0.8\mathrm{g}\text{ Charoal }\to 1050 \mathrm{mg} {\mathrm{CH}}_3\mathrm{CoOH}$

$\text{ Ig charcoal }\to \frac{1050}{0.8}\mathrm{mg} {\mathrm{CH}}_3\text{ cosh }$

$=1312.5 \mathrm{mg} {\mathrm{CH}}_3\mathrm{COOH}$

$=1.31\mathrm{g} {\mathrm{CH}}_3\mathrm{COOH}$