determine the solubility of banzoic acid in water and calculate its Delta H
Answers
Answer:
As solubility is the concentration of a solute in a saturated solution you have to saturate a solvent with you solute and measure the resulting concentration. You can do this by:
Make sure you have a saturated solution of benzoic acid in water (with solid benzoic acid present). This can be achieved through stirring an excess of the solute in the solvent. If all solid is dissolved more should be added and ample time be given to allow equilibrium to be reached.
Withdraw sample and remove all remaining solid benzoic acid through filtration or centrifugation.
Dilute sample and determine concentration using an available method. Calculate the concentration of the saturated solution with the dilution factor used.
It's a good idea to perform the experiment in replicates and make sure conditions such as temperature is kept constant throughout the assay.
Solubility of benzoic acid at different temperature is as follows :-
Temperature (95 °C) -> 68 g/L Solubility
Temperature (90 °C) -> 45.5 g/L Solubility
Temperature (0 °C) -> 1.7 g/L Solubility
The solubility of compound is determined by the amount of material dissolved in a certain amount of solvent.
For Benzoic acid, the ph of the water matters. At high pH, the benzoic acid forms a soluble salt hence the solubility increases as the pH increases. At low pH, benzoic acid doesn’t dissolve as much.