how can i dissolve both the anionic surfactant ( SDS ) and salt ( NaCl ) in 5 ml water without precipitating salt or surfactant or sticking to the wall or bottom of the beaker?
Hi Ali,
I recognize the case..... trying to do multiple things in one go... When dissolving chemicals, always check:
1. If your target concentration does not exceed the solubility limit of each of your components? So, check SDS solubility.
2. The sum of components does not exceed the solubility of each component, so if both components do not hinder each others solubility? Which means check if NaCl lowers the solubility of SDS (I guess it does)?
If you are sure the target concentration is below the solubility limit, than the effect you're seeing is kinetics of dissolution. This is easy to fix...
1. If you want to make the solution by adding solids and next water, use some mild heating to speed up dissolution (e.g. water bath at 45°C for 2 hours).
2. If you only need to obtain a solution of both and the pathway to get there is not important, first make a concentrated SDS and NaCl solution separately, next mix them in any ratio you like.
Hope this helps, kind regards, Leo
Alas Sangyoon Ji, pH has no effect on solubility, at least if one stays in the normal pH range... from 1-14. Both NaCl and SDS have pKa values that are not affected in this range as they are very weak bases. Acidic conditions in this case may further increase the hydrolysis of SDS into laurylalcohol, so please stay away from acidic pH.
- Badges
- Science topic