# salt and vinegar



## cutlass69 (Jan 15, 2017)

has anyone here tried the salt and vinegar method some of these acids are hard to get hold of thanks


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## FrugalRefiner (Jan 15, 2017)

There are several threads on the subject. Try a search for salt vinegar. I got 140 hits.

Dave


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## butcher (Jan 15, 2017)

One mole vinegar (acetic acid) CH3COOH plus one mole of salt (sodium metal chloride salt) NaCl gives a mixture of one mole of hydrochloric acid (muriatic acid) HCl and one mole of sodium acetate (CH3COONA).
CH3COOH + NaCl = CH3COONA + HCl

Note this is a reaction with carbon involved (an organic chemical reaction). vinagar is a weak acid, and with the carbon involved, I personally would prefer to make HCl in situ without using an organic acid, A stronger acid like H2SO4 would be my choice.

With one mole of sulfuric acid H2SO4 and one mole of sodium chloride salt NaCl, we produce two moles of hydrochloric acid HCl and one mole of sodium sulfate. this will work fine for gold (note silver can form sulfates).
If a purer HCl is needed we can distil off the HCl leaving the Na2SO4 behind in the reaction vessel (bubble HCl gas into a small amount of water)

2NaCl + H2SO4 → Na2SO4 + 2HCl
Here we do not have the carbon to deal with this is an (inorganic chemical reaction no carbon involved.) and get a stronger acid that will work better for gold recovery.

Personally, I would not use vinegar in the reaction, But I keep a bottle of vinegar in the lab just to neutralize caustic soda (NaOH) on the skin, likewise I keep a bottle of saline for the eyes on the shelf, along with baking soda and others, within easy reach where I can find them with my eyes closed just in case of an emergency situation (chemical and first aid kit on the shelf)...

I have made several posts on this subject with much more detail.


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## aga (Jan 15, 2017)

butcher said:


> One mole vinegar (acetic acid) CH3COOH plus one mole of salt (sodium metal chloride salt) NaCl gives a mixture of one mole of hydrochloric acid (muriatic acid) HCl and one mole of sodium acetate ...


The bits doing the work are the ions that occur when these things are dissolved in water, namely the Cl-. and H+.

Acetic is a relatively weak acid with a pKa of around 5. That means that it does not fully dissasociate into H+ and an acetonium anion, when dissolved in water.

Because of this, chances are that you'd need more vinegar than calculated.

HCl has a pKa of < 0, meaning that it completely dissassociates into H+ and Cl- in water (making calculation of quantites required much easier).

How much it disassociates (pKa) is the technical definition of a 'strong' (pKa<0) and a 'weak' acid (pKa>0).
For example, Hydrofluoric acid is a 'weak' acid (pKa ~3) yet it dissolves almost everything, including glass.

Personally i've tried the salt & vinegar (then bleach) experiments. It works, but when compared to the strong mineral acids, it's pretty much inferior in terms of speed/effectiveness.


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