Appropriate container for dosing Sodium Hydroxide?

[Nerdist Aquarist]

I'm going to start dosing Sodium Hydroxide in addition to my 2 part mix in effort to raise pH. What's a good container to keep the solution in? Apparently glass is a no no, and some plastics are too. What about acrylic?

 

[redfishbluefish]

If your mixing dry sodium hydroxide with water, I'd only do it in glass. This reaction is very exothermic....it gets hot. Not sure I'd trust plastics. I'd get a glass bottle with a glass stopper.

 

[Nerdist Aquarist]

I'm reading glass is not recommended as it does react.

 

[blasterman]

I just kept mine in a plastic juice jug. You aren't dealing with fluorine based acids. Its lye.

It gets warm when mixed. So....you keep it immersed in cold water when mixing it. No big deal.

Just a warning, but I've tried dosing sodium hydroxide and found it full of other stuff like phosphate. If you are dosing it try to get pharma grade.

 

[Randy Holmes-Farley Verified Community Expert]

Polyethylene and polypropylene are not impacted by high pH. Just make sure you do not get it too hot from the heat of dissolution. Avoid polycarbonate.

 

[Mjl714]

Polyethylene and polypropylene are not impacted by high pH. Just make sure you do not get it too hot from the heat of dissolution. Avoid polycarbonate.

How would you recommend keeping polyethylene containers cool while mixing the sodium hydroxide and sodium sulfate? I could set my polyethylene containers on ice packs. Would mixing slowly help?

 

[JohnMzreef]

Apparently glass is a no no

Can you explain?
(I keep mine in a little yeast jar)

 

[Mjl714]

Can you explain?
(I keep mine in a little yeast jar)

I’m with you, I don’t understand why glass would have an issue.

 

[Randy Holmes-Farley Verified Community Expert]

How would you recommend keeping polyethylene containers cool while mixing the sodium hydroxide and sodium sulfate? I could set my polyethylene containers on ice packs. Would mixing slowly help?

Just make sure they are nearly full of cool water, rather than adding a little water to the solid.

 

[Randy Holmes-Farley Verified Community Expert]

I’m with you, I don’t understand why glass would have an issue.

Glass dissolves at very high pH, releasing silicate into the water.

I know people think it inert, but its not. With a strong sodium hydroxide solution (stronger than recommended for my recipes), you can visibly etch the glass.

Glass Cutters Are for Tools: How to Dissolve Glass Using Sodium Hydroxide

Glass is one of the least reactive substances known to chemistry. It is the standard container material for almost all lab chemicals because it's so inert. But there are a couple of substances that have strong reactions with glass. Sodium hydroxide, aka solid drain cleaner or lye, can easily be...

mad-science.wonderhowto.com

 

[Courtney Aldrich]

Glass is fine at room temperature. I've stored solutions of sodium hydroxide in glass for years (10+ years). The stopper should be plastic since the glass stopper can become frozen over time.

 

[Randy Holmes-Farley Verified Community Expert]

Glass is fine. I've stored solutions of sodium hydroxide in glass for years. The stopper should be plastic since the glass stopper can become frozen over time.

Did you ever analyze the solutions for silicate?

Corrosion of silicate glasses by alkaline solutions Communication 4. Corrosion of glasses by solutions of various hydroxides - Russian Chemical Bulletin

1. The hydroxides examined in the present investigation may be arranged in the following order with respect to corrosive action on glasses: KOH > LiOH > NH4OH > Ba(OH)2 > Sr(OH)2 > Ca(OH)2. 2. Sodium hydroxide corrodes silicate glasses of all compositions to a greater extent than all the other...

link.springer.com

 

[Mjl714]

Glass dissolves at very high pH, releasing silicate into the water.

I know people think it inert, but its not. With a strong sodium hydroxide solution (stronger than recommended for my recipes), you can visibly etch the glass.

Glass Cutters Are for Tools: How to Dissolve Glass Using Sodium Hydroxide

Glass is one of the least reactive substances known to chemistry. It is the standard container material for almost all lab chemicals because it's so inert. But there are a couple of substances that have strong reactions with glass. Sodium hydroxide, aka solid drain cleaner or lye, can easily be...

mad-science.wonderhowto.com

You’re right, probably due to glass strength and great heat tolerance i did not know this. Thanks for informing.

 

[Gogi]

@Randy Holmes-Farley I didn't quite understand from above. Would a borosilicate beaker be ok for mixing (not storing) your standard (or 1.5x) solution your sodium hydroxide solution?

 

[Randy Holmes-Farley Verified Community Expert]

@Randy Holmes-Farley I didn't quite understand from above. Would a borosilicate beaker be ok for mixing (not storing) your standard (or 1.5x) solution your sodium hydroxide solution?

Yes. The hydroxide concentration is not high enough to cause rapid etching. I just did not want folks to think of glass as inert. A little silicate, if any releases, will not hurt anything. I regularly dosed it. Other things in glass are too low to worry about or nontoxic (like borate).