Shelf life of Sulphuric Acid drain cleaner for CO

[Yaffle]

As the title says, I found an old but new sealed bottle of 93% sulphuric acid drain cleaner (probably at least 20 years old). Concentration above 15% is regulated now in the UK so I can't easily replace it.

It's in the original plastic bottle and still sealed.

I would assume it's still OK, I know glass is better but it is what it is.

I've read online about storing it and the manufacturer product sheet lists it as stable - but this is super old.

Any thoughts from people here with chemical knowledge if it would still viably produce CO when combined with Formic acid?

 

[Yaffle]

Bump

 

[DepressedChemMajor]

If it's sealed, it should be fine, as long as it hasnt touched anything organic

 

[Praestat_Mori]

Sulfuric acid is hygroscopic (=it attracts water) but as long as the bottle is sealed and there is no contact with humidity or other substances, nothing's gonna happen to it.

 

[Yaffle]

If it's sealed, it should be fine, as long as it hasnt touched anything organic

Sulfuric acid is hygroscopic (=it attracts water) but as long as the bottle is sealed and there is no contact with humidity or other substances, nothing's gonna happen to it.

Thanks both

 

[Intoxicated]

It's in the original plastic bottle and still sealed.

Concentrated H2SO4 can slowly react with HDPE, so some contamination is possible, but it shouldn't be critical for producing CO.

 

[Yaffle]

Concentrated H2SO4 can slowly react with HDPE, so some contamination is possible, but it shouldn't be critical for producing CO.

If only I could easily buy fresh.

The only other option is to buy an expensive CO meter and test the setup first.

 

[Intoxicated]

If only I could easily buy fresh.

You don't need high purity H2SO4 to produce CO. Since high purity is not required in many cases, HDPE is commonly used for storing H2SO4. Some chemical suppliers can use fluoroplastics (PTFE, FEP, PFA) to maintain high purity of sulfuric acid, but such a usage is probably uncommon. Fluoroplastics are commonly used for storing extremely corrosive substances like fluorosulfuric acid and fluoroantimonic acid which cannot be safely contained in glass or polyethylene vessels.