Sodium Carbonate-is this mono or anhydrous

[absalom1951]

I purchased this from the internet, thinking it would be labeled indicating either mono or anhydrous. But it isn't. Plan on mixing up some D72. The label states dense, but that means nothing to me. The photo shows the only label on the pack. Any help is greatly appreciated.

 

[GeorgK]

According to the CAS number (497-19-8) it is anhydrous.

 

[absalom1951]

Thanks GeorgK. Very helpful.

 

[Don_ih]

I purchased this from the internet

A good, cheap source for a large amount of sodium carbonate is Ph+ pool chemical - just check the ingredients to make sure it's sodium carbonate (most list it). I assume it's not anhydrous - but the amount of carbonate in D72 isn't exactly critical.

 

[absalom1951]

I have a container of pool and spa ph increaser which is 97% sodium carbonate but it has blue crystals scattered through it. Would the blue crystals alter the formula? All I can gather from the label is that the Blue crystals are minerals.

 

[Don_ih]

I have a container of pool and spa ph increaser which is 97% sodium carbonate but it has blue crystals scattered through it. Would the blue crystals alter the formula? All I can gather from the label is that the Blue crystals are minerals.

I wouldn't really trust the blue crystals. I'd only use something that was fairly obviously entirely sodium carbonate - which I think most are (because it's the cheapest thing for them to do).

Of course, if you try the stuff and it seems to have no impact, then it'll probably be fine.

 

[Scott J.]

According to the CAS number (497-19-8) it is anhydrous.

Bingo. Georg's got it.

Regarding the "dense" aspect of the name: For crystalline substances, this is generally an indication of physical form. A "dense" version typically has a coarser, sugar-like texture that has a higher bulk density, whereas a "light" version will typically have a finer, flour-like texture with a lower bulk density. Both versions are chemically identical and can be used interchangeably, with the caveat that the dense version may take a little longer to dissolve.

 

[absalom1951]

I wouldn't really trust the blue crystals. I'd only use something that was fairly obviously entirely sodium carbonate - which I think most are (because it's the cheapest thing for them to do).

Of course, if you try the stuff and it seems to have no impact, then it'll probably be fine.

I think for the moment I'll put it on the shelf and maybe this winter when the wind is blowing and snow falling I might try it. I suppose the worse it can do is to leave blue spots.

 

[absalom1951]

Bingo. Georg's got it.

Regarding the "dense" aspect of the name: For crystalline substances, this is generally an indication of physical form. A "dense" version typically has a coarser, sugar-like texture that has a higher bulk density, whereas a "light" version will typically have a finer, flour-like texture with a lower bulk density. Both versions are chemically identical and can be used interchangeably, with the caveat that the dense version may take a little longer to dissolve.

Thanks for this explanation. Now for me to remember this for the next time I run across the word

 

[fgorga]

Another readily available and inexpensive source for sodium carbonate is the grocery store. Good old fashioned washing soda is sodium carbonate decahydrate. Look for it in the laundry section.

 

[absalom1951]

Another readily available and inexpensive source for sodium carbonate is the grocery store. Good old fashioned washing soda is sodium carbonate decahydrate. Look for it in the laundry section.

That's what I call a multi purpose "tool". After developing prints I can wash my clothes in it- I should re phase this. I will not wash my clothes in the D72. Think I'll quit before I really get in a corner. Thanks fgorga

 

[uranylcation]

I have a container of pool and spa ph increaser which is 97% sodium carbonate but it has blue crystals scattered through it. Would the blue crystals alter the formula? All I can gather from the label is that the Blue crystals are minerals.

The blue cystals are probably copper sulfate

 

[john_s]

Might the blue crystals be dessicant, like the blue crystals in cat litter? They indicate dampness by changing colour. Not that it would matter if it's going into the pool, I guess. Some pool chemicals are quite impure, and I'd be wary of using them for photo use.

 

[absalom1951]

As for now I will put the blue crystal sodium carbonate on the shelf. I may experiment with it at a later date. If I do experiment with it I will post my results here. Thanks for all the information.

 

[Don_ih]

As for now I will put the blue crystal sodium carbonate on the shelf. I may experiment with it at a later date. If I do experiment with it I will post my results here. Thanks for all the information.

It may have no impact, especially at the low concentration once you've diluted the carbonate in first the 1 litre of water and then the next 2 for use with paper. Copper sulfate makes sense, since it's used in pools, also. That might have an impact on the print.