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