`50 ml` of `1 M`, oxalic acid is shaked with `0.6 gm` of charcoal. The final concentration of this solution after adsorption has been found to be `0.4 M`. The amount of oxalic acid absorbed per `gm` of charcoal is

Explanation

1 M oxalic acid solution means 1 mole of oxalic acid or 126 g present in 1000 mL solution.
`:.` 50 mL of 1 M solution will contain oxalic acid
`=126/1000 xx 50 = 6.3 g`
Concentration of solution after adsorption = 0.4 M
1000 mL of solution will contain oxalic acid `=0.4 xx 126 = 50.4 g`
50 mL of solution will contain oxalic acid
`=(50.4)/(1000) xx 50 = 2.52 g`
Amount of oxalic acid adsorbed by 0.6 g of charcoal
`= 6.3 - 2.52`
`=3.78 g`
Amount of oxalic acid adsorbed per gram of charcoal
` =(3.78)/0.6 = 6.30g`