Sulfuric Acid substitute

[brucemuir]

Hey folks,
I'm putting together the components to give the Ilford process for BW reversal a whirl and of course I'm having problems finding stuff again.

I'm going to be using the indicated permanganate bleach and saw where someone has suggested using sodium bisulfate as a replacement/substitute for the sulphuric acid needed for solution B of the bleach.

Has anyone done this and can give me any direction or thoughts on this approach.

I've been trying to find the sulfuric acid from local sources to keep things reasonable but no luck with auto parts stores and the other "alternative" sources.

I can get it from the formulary but am seeing what you guys say.

Thanks.

 

[Christopher Walrath]

Check out your local Fisher Auto Parts and ask them to order in 1 of a part number DC1. It's a 5-qt size of Automotive Battery Acid (Sulfuric Acid). Tell them Chris from MILFRD sent you. Find a store near you.

 

[brucemuir]

closest one is about 30-40 minutes away.
my be an option.
thanks for that tip

 

[Christopher Walrath]

You're welcome.

 

[Denis K]

You would have to do the molar-math but don't pool supply stores sell sulfuric acid?

Denis K

 

[dancqu]

Sodium bisulfate may be used to replace
sulfuric acid: by weight 2.82 parts equals
1.00 part of pure sulfuric acid.

Be careful, keep lid tight and weigh rapidly.
Hydroscopic and Poisonous. Dan

 

[Jordan]

And extremely corrosive.

 

[brucemuir]

Jordan,
Your site was where I first saw the possibility.

I understand the dangers but am not a chemist obviously. I do understand the proper order of adding the acid to the water.

Would using the sodium bisulfate be any more dangerous than the liquid sulphuric acid?

The sodium bisulfate is so much easier to obtain.

 

[Jordan]

Bruce -- no, I don't think it's any more dangerous, but it is easy to get lulled into a false sense of safety by a free-flowing, white powder. Just handle it cautiously and try to use cold water to start, as heat will probably be generated in dissolution.

 

[snallan]

Jordan,
Would using the sodium bisulfate be any more dangerous than the liquid sulphuric acid?

Sodium bisulfate is corrosive, but compared to the parent sulphuric acid it is a weak acid. However should still be used with care.

Concentrated sulphuric acid is is an 18 Molar solution, so 1ml of concentrated acid contains approx. 1.8g of sulphuric acid, using Dan's equivalence above requires around 5g of sodium bisulphate. I go with a slight excess and actually use around 6g of the bisulphate in place of each millilitre of concentrated sulphuric acid