Stirring Bars Are Superstition?

2 dcminter 6 9/6/2025, 5:03:55 PM science.org ↗

Comments (6)

rolph · 11h ago
the primary function is to quickly dissolve reactants rather than wait for passive dissolution to occur.

very few competent chemists would elect to commence a reaction, with a large amount of reactant still undissolved at the bottom of a vessel.

the stir bar is often left in, through the rest of the reaction.

dcminter · 11h ago
But here's the money quote from Mr Lowe's take on the paper: "If you were presented with these data without being told that stirring was the variable under consideration, you’d have to conclude that whatever it was, it wasn’t really that important, honestly."

i.e. it doesn't necessarily speed it up or change the yield. So why do you care if the reactant's still on the bottom of the vessel in that case?

rolph · 10h ago
what is not being considered is the preparation often starts with a volume of reactant on the bottom of a vessel slowly dissolving according to physical soluability.

if you start a reaction like that without stirring, you will see a big difference in product yeild.

dcminter · 9h ago
Not in fact true, or not as a general case, according to this paper, which is why this paper is interesting.
rolph · 8h ago
actually it is very true, the "study" concerned 326 reactions of all reactions available. if reactant is undissolved it is unavailable to the reaction, thus uncontributary to molar ratio.

this will limit yield, as well as creating an impromptu addition of a secondary quantity of reactant

this paper is qwackery, mr lowe demonstrates in this submission, a paucity regarding chemical reaction kinetics, and fails to cultivate a critical interpretation due to this lack of knowledge.

dcminter · 8h ago
Ok, we're done here.