The Vespiary

The Hive => Newbee Forum => Topic started by: kuykur on October 10, 2004, 08:33:00 AM

Title: How can I tell my formic acid conc.?
Post by: kuykur on October 10, 2004, 08:33:00 AM
I got a bottle of formic acid recently, but there's no sign on the label about the purity/concentration of it.
How can I tell more or less accurately with a simple method? And if it happends to be too dilluted, can I just boil it to get to the 85% needed for the performic oxidation of isosafrole?
Title: Density->Concentration
Post by: Nicodem on October 10, 2004, 11:12:00 AM
Get yourself an aerometer and mesure the density of the formic acid. That's the easiest and fasted method to measure the concentration of most solvents.

Title: titration
Post by: hypo on October 10, 2004, 11:12:00 AM
> How can I tell more or less accurately with a simple method?

titration of a diluted sample - get a burette and a graduated flask.
formic acid is usually titrated against KMnO4, but if you can't get
that, then titration against a strong base will work too.

> can I just boil it to get to the 85%

no - bp of formic acid is 100.7°C! you could have found that out yourself,
lazy bastard!

Title: Formic Acid Density/Concentration Table
Post by: Rhodium on October 11, 2004, 01:00:00 AM
(https://www.thevespiary.org/rhodium/Rhodium/hive/hiveboard/picproxie_docs/000535158-hcooh_density-conc.gif)