You have a solution that contains 1.0 g of oxalic acid dissolved in 100 mL of ether. This solution is placed in a separatory funnel, and then washed with 100 mL of water. Diethyl ether and water are immiscible solvents. The solubility of oxalic add in water is 143 g per liter, and the solubility of oxalic acid in ether is 14.0 g per liter.
A. How much oxalic acid is removed from the ether by this extraction? Express your answer in grams and in percent.
B. Do you think that this is an efficient way to remove oxalic acid from ether?

Since you have 1 g of oxalic acid in your mixture, and it is very soluble in water (143 g/L or 14.3 g in 100 ml), practically all the acid will be recover in water.

The oxalic acid, also is slightly soluble in ether, but just 14 g /L or 1.4 g in 100 ml.

These data shows that the oxalic acid posses 10 times more solubility in water than in ether.

If in your mixture you have 1 g, so practically 0.9 g (the 90 %) are going to be dissolved in water and just 0.1 g (the 10 %) in ether.