Question
Posted on: March 6 2013How can we avoid precipitation in next solution? Salicylic Acid 6 g boric acid 8 g Isopropanol 120 ml Water up to 200 ml
Answer
The solubilities of salicylic acid are the following: 1 g in 460 ml of water and 1 g in 4 in alcohol. Boric acid is soluble 1 to 18 ml of water or ethanol; 1 on 3 in boiling water; Solubility in isopropanol is not reflected.
If we do not adopt a difference in solubility between ethanol and isopropanol then for 8 g boric acid 144 ml of water or alcohol is required. Of course, the question of the mutual ï of the two products remains on their solubility. A first attempt showed that after 1 day of storage in the dissolving, a precipitate was formed, which presumably consists of boric acid. This led us to slightly alter the isopropanol/water ratio by reducing the amount of isopropanol to 100 ml. Under these conditions, the solution remained clear when storing.
for the preparation we can proceed as follows: Apply 100 ml of boiling water in a bottle and dissolve on 8 g boric acid. After cooling to a temperature of approximately 70 ° C add 120 ml isopropanol in which 6 g of salicylic acid have been dissolved. Close the bottle and mix front faces. Allow to cool.
If we do not adopt a difference in solubility between ethanol and isopropanol then for 8 g boric acid 144 ml of water or alcohol is required. Of course, the question of the mutual ï of the two products remains on their solubility. A first attempt showed that after 1 day of storage in the dissolving, a precipitate was formed, which presumably consists of boric acid. This led us to slightly alter the isopropanol/water ratio by reducing the amount of isopropanol to 100 ml. Under these conditions, the solution remained clear when storing.
for the preparation we can proceed as follows: Apply 100 ml of boiling water in a bottle and dissolve on 8 g boric acid. After cooling to a temperature of approximately 70 ° C add 120 ml isopropanol in which 6 g of salicylic acid have been dissolved. Close the bottle and mix front faces. Allow to cool.