Question

50 mL of 1 M oxalic acid (molar mass =126) is shaken with 0.5 g of wood charcoal. The final concentration of the solution after adsorption is 0.5 M. What is the amount of oxalic acid adsorbed per gram of carbon?

• A. 3.15
• B. (6) 1.575
• C. 6.30
• D. 12.60

Answer 1

Answer: (C)

Weight of 50 mL of 1 M oxalic acid
$ w=\frac{NEV}{1000} $
(Here, $ N=m $ ) $ =\frac{1\times 126\times 50}{1000} $
$ =6.3\,g $
Similarly weight of 50 mL of 0.5 M oxalic acid
$ =\frac{0.5\times 126\times 50}{1000} $
$ =3.15\,g $
Adsorbed oxalic acid on 0.5 g charcoal
$ =6.3-3.15 $
$ =3.15g $
Amount of oxalic acid adsorbed per gram of charcoal
$ =\frac{3.15}{0.5} $
$ =6.3 $