Does Boric Acid Expire ??? or become B2O3 after 5-10 years on its own???


by mubashirmansoor
Tags: acid, b2o3, boric, expire
mubashirmansoor
mubashirmansoor is offline
#1
Feb6-12, 01:25 PM
P: 259
Hi,

I have had some Boric acid (99.9%) bought a very long time ago... The expiry date was in 2006...

I have used it recently and it is as if it's pure B2O3. Is that even possible??!! How could it be???! or is there something I am missing?

The experiment I had done was heating some of this Boric acid along with certain glass modifiers (Na2O and PbO) and the density as well as other optical properties of resulting glass are as if I have used B2O3 in the batch. There hasn't been any weight loss associated with the decomposition of Boric acid either!

thanks in advance...
Phys.Org News Partner Chemistry news on Phys.org
Recycling industrial waste water: Scientists discover a new method of producing hydrogen
Making radiation-proof materials for electronics, power plants
A greener source of polyester?cork trees
Dr_Morbius
Dr_Morbius is offline
#2
Feb6-12, 05:30 PM
P: 155
When kept at room temperature Boric Acid should last forever. Sometimes though the term "Boric Acid" can be applied to more than one chemical so you should check the label and see what the chemical formula on it says.

http://en.wikipedia.org/wiki/Boric_acid
mubashirmansoor
mubashirmansoor is offline
#3
Feb6-12, 06:18 PM
P: 259
its Analytic grade H3BO3...

It has been at room temperature in a poorly sealed plastic container.

Borek
Borek is offline
#4
Feb7-12, 02:05 AM
Admin
Borek's Avatar
P: 22,659

Does Boric Acid Expire ??? or become B2O3 after 5-10 years on its own???


Quote Quote by mubashirmansoor View Post
The experiment I had done was heating some of this Boric acid along with certain glass modifiers (Na2O and PbO) and the density as well as other optical properties of resulting glass are as if I have used B2O3 in the batch. There hasn't been any weight loss associated with the decomposition of Boric acid either!
When heated, boric acid starts to decompose below 200C, I don't see how it could not lose the water - unless it reacted with Na2O present. Perhaps properties of the glasses you are referring to have error margins wide enough so that they are not an indicator of what have really happened?

To answer directly your question: no, it won't expire nor change to B2O3, it is quite stable.


Register to reply

Related Discussions
boric acid Chemistry 2
How to convert boric acid to boric oxide Biology, Chemistry & Other Homework 5
Boric Acid Esters Chemistry 8
Boric acid used to provide heat protection? Materials & Chemical Engineering 1