Question

2.0 g of activated charcoal is added to 100 mL of 0.5 M acetic acid (molar mass 60 g mol\(^{-1}\)), shaken well and filtered. The concentration of solution is reduced to 0.4 M. How many grams of acetic acid is adsorbed on charcoal per gram?

• A. 0.1
• B. 0.2
• C. 0.3
• D. 0.15

Hint:

To find the amount adsorbed on a surface, subtract the final concentration from the initial concentration and relate the result to the mass of the adsorbent.

Answer 1

The Correct Option is C

- Initial amount of acetic acid = \(0.5 \, \text{M} \times 100 \, \text{mL} = 0.5 \, \text{mol/L} \times 0.1 \, \text{L} = 0.05 \, \text{mol}\). - Final amount of acetic acid = \(0.4 \, \text{M} \times 100 \, \text{mL} = 0.4 \, \text{mol/L} \times 0.1 \, \text{L} = 0.04 \, \text{mol}\). - Amount adsorbed = \(0.05 - 0.04 = 0.01 \, \text{mol}\). - The amount of acetic acid adsorbed on 2.0 g of charcoal = 0.01 mol. - Molar mass of acetic acid = 60 g/mol, so the mass adsorbed = \(0.01 \, \text{mol} \times 60 \, \text{g/mol} = 0.6 \, \text{g}\). - Grams adsorbed per gram of charcoal = \(\frac{0.6 \, \text{g}}{2.0 \, \text{g}} = 0.3\).