Stirring a reaction mixture using a overhead stirrer on a bit larger scale.
In case when we have a slurry, high viscosity reaction mixture, the most often used magnetic stirrers usually fail to stir the whole reaction mixture and we have to switch to these overhead stirrers that do the job.
The above seen reaction was an oxidation with sodium periodate where a solid, high molar mass and poorly soluble salt is used as a reactant and sodium iodate is formed with similar physical properties. The reaction was performed under nitrogen atmosphere what was maintained by introducing a constant slow flow of nitrogen gas through a needle, as seen of the last picture. And this gas could be seen on the first picture, escaping from the reaction through the gas bubbler at the top.