Question

50 ml of 1M oxalic acid is shaken with 0.5 g of wood charcoal. The final concentration of the solution after adsorption is 0.5 M. Calculate the amount of oxalic acid adsorbed per gram charcoal.

• A. 1.575 g
• B. 0.05 g
• C. 3.15 g
• D. None

Answer 1

The correct option is

C

6.3 g

No. of moles in 50 ml of 1 M oxalic acid is = $\frac{50L}{1000}\times 1M$ =0.05 moles of oxalic acid.

After adsorption, remaining moles of oxalic acid=$\frac{50L}{1000}\times 0.5M$ =0.025 moles.

Thus, moles that adsorb on charcoal is =0.05−0.025=0.025 moles of oxalic acid.

Therefore, 0.025 moles of oxalic acid adsorb on 0.5 g of charcoal.

1 gram of charcoal moles adsorb=$\frac{0.025}{0.5}$ =0.05 moles of oxalic acid.

Amount of oxalic acid adsorbed per gram of charcoal = 0.05×126g/mole=6.30grams

Thus, 6.30 g of oxalic acid adsorb per gram of charcoal.

Hence, option C is correct.