Pickling Strength

You really should be using 10% Hydrochloric Acid for pickling!

Yea, you can use use it. You can also use Brown Sauce. Moles with brown sauce,yum, yum.

Oops, more Flak.

Norm

About 10% by volume.

Alan

A mole of sulphuric acid weighs 98.08 grams. That's about 52.62 millilitres of of your stock acid.

For workshop purposes, call it 100 grams or 50 ml.

One litre of a molar solution contains one mole of acid, so a molar solution is about 10% acid by weight, or 5% by volume.

When diluting acids (especially sulphuric acid) use eye protection and rubber gloves, wear a plastic or rubber apron and old clothes, and avoid splashes. Have some sodium bicarbonate or washing soda powder handy in case of spills.

Note also that sulphuric acid is poisonous as well as corrosive.

To make a litre of 1M or molar solution, put 700 ml of water into a suitable container which is big enough to comfortably hold one litre.

Weigh or measure one mole of acid into another suitable container. Put the stock bottle of acid away, and then slowly add the mole of acid with stirring to the water. It will get hot.

Let it cool, then top up to one litre with more water, stirring carefully - note that you are adding water to dilute acid here.

This works up to about 5 M strength, ie add two moles for two molar and so on, and just multiply everything for larger volumes. The solution will get very hot, especially at the higher end of the concentration range when it will be nearly boiling.

Making up solutions of sulphuric acid stronger than about 5 M (molar) ~ 30% is very dangerous, as the acid/water mixture would boil. In some proportions the mixture will explode violently, producing a mist of boiling sulphuric acid. I will advise if you need to make up such a solution (unlikely), but not on-list.

Some of that might seem silly or unnecessary, but if you do it that way every time you are unlikely to go wrong. And I promise, going wrong can be very nasty indeed. Been there, the tee-shirt is all holes, and I was lucky. Wear eye protection if nothing else, it can save your life.

A small clean dry polyethene or polypropylene (it will have the letters PE or PP moulded into it near a recycling mark) plastic kitchen / measuring jug is suitable to hold the acid while you weigh/measure it. Wine makers suppliers also sell suitable plastic measuring cylinders.

PP or PE is also okay for a mixing vessel for up to 2 M or so solutions, but if you are trying to make a more concentrated solution it might well get too hot, so use glass or glazed crockery instead.

And above almost all else, do not add acid directly from the stock bottle to the water. Always measure it out first.

I have no idea what strength you would use for a pickle though - pickling what? temperature? time? onions?

Hydrochloric acid is easier, and much less dangerous to dilute than sulphuric acid. Conccentrated hydrochloric acid, eg "spirits of salts", is about 35% HCl, more will not dissolve.

To make a 10% general pickling solution, add 2.5 volumes of water to one volume of concentrated acid while stirring and allow to cool.

Add one volume of HCl acid to 6 volumes of water for a 5% solution for cleaning toilets etc.

AaargH -= the other way around, of course. Add the acid to the water.

Though it isn't that important with hydrochloric acid.

(beats himself with stick)