HCl Bright Yellow

[Miami Reef]

I store my HCl (hydrochloric acid) in a pickle jar.

I see bright yellow condensation. It was stored in this jar for months without yellowing, so I’m not sure why it is now producing this bright, yellow fluid.

What is it?

 

[Randy Holmes-Farley Verified Community Expert]

I suspect it may be traces of dissolved iron, perhaps oxidizing to the ferric form that is more highly colored than the ferrous form.

Home v2

Veolia's household hazardous products collection centers in Sutton and Westfield, Massachusetts

www.nedt.org

"Usually, muriatic acid includes iron impurities, giving it a yellow color instead of HCI’s colorlessness."

 

[Miami Reef]

I suspect it may be traces of dissolved iron, perhaps oxidizing to the ferric form that is more highly colored than the ferrous form.

Home v2

Veolia's household hazardous products collection centers in Sutton and Westfield, Massachusetts

www.nedt.org

"Usually, muriatic acid includes iron impurities, giving it a yellow color instead of HCI’s colorlessness."

Thank you.

Just out of curiosity, which form of iron is more available to seawater organisms? Does iron frequently alternate forms in tanks?

 

[Randy Holmes-Farley Verified Community Expert]

Thank you.

Just out of curiosity, which form of iron is more available to seawater organisms? Does iron frequently alternate forms in tanks?

That's a good question without a perfect answer. There are many complexities and studies of it, including solubility differences, different binding by siderophores, different binding by uptake proteins, etc.

I had a full answer to this in some thread, but cann't fined it. Here's from an older response:

This paper discusses how ferrous iron that gets oxidized can become less bioavailable

ftp://ftp.soest.hawaii.edu/glazer/Chen%20References/Papers1/Pham%202008%20Oxygenation%20of%20Fe%20II.pdf