Hi again! While the titration video is waiting for the post-production, a new technique video is ready. This is preparing a solution from solid. Again, the first thing was to find good resources – these were Vogel’s Textbook of Quantitative Inorganic Analysis and the IUPAC Gold Book (standard solutions). I thought that despite that sodium hydroxide is not a primary standard, the main point is to teach the students how to prepare a solution from solid, and that sodium hydroxide would match the video on titration quite nicely. It is emphasised in the video that this is not a standard solution, and that it has to be standardised (titration with a secondary standard as titrant).
So the video is on making a 0.100 M NaOH aqueous solution. As for titration, the protocol was the first thing to do – I wrote down the procedure and the main points to remember. Generally, the main thing was to transfer the solid to the flask quantitatively, which basically means to rinse with deionised water everything that had contact with the solid. Work in the lab was quite smooth and didn’t cause trouble – especially that all the quality issues were solved in the titration video.
The video I’m sharing with you now is the first, rough version. It has the audio and I hope it’s easy to follow. Please note, that the video will be re-shot with sodium carbonate instead of hydroxide, as I want to avoid any confusion with regard to using NaOH for standard solutions. Sodium carbonate is a primary standard and hence will leave no doubts. However, I wanted to share this video anyway, as the procedure for Na2CO3 will be pretty much the same. So please tell me if you find any mistakes and I’ll avoid them in the second version – the one with carbonate. One doubt that I’ve had is whether gloves should be used. For 0.1-molar NaOH there is no need, but solid NaOH is a different story – is it dangerous enough to use gloves though? Of course, this question is easy for carbonate and for that video I won’t be using gloves.
So yeah, please let me know what you think. As I said, the solid will be replaced with sodium carbonate but this won’t change the procedure much. Enjoy watching!