Pickle

Technically 1:10? But that may well result in 22 litres unless there is a change in volume on mixing.

A check on the density of the resultant solution would provide the actual volume, if the density of the 95% part is known.

From my Merck chemical table booklet, there is a contraction in volume when diluting 97.5% sulphuric to battery acid concentration.

2.666 litres of acid mixed with 7.895 litres of water yields only 10 litres of battery acid.

I suggest you aim for about 18 litres by mixing the acid into water and dilute the resultant mixture to 20 litres when cooled.

Technically 1:10? But that may well result in 22 litres unless there is a change in volume on mixing.

A check on the density of the resultant solution would provide the actual volume, if the density of the 95% part is known.

From my Merck chemical table booklet, there is a contraction in volume when diluting 97.5% sulphuric to battery acid concentration.

2.666 litres of acid mixed with 7.895 litres of water yields only 10 litres of battery acid.

I suggest you aim for about 18 litres by mixing the acid, with stirring, into water and dilute the resultant mixture to 20 litres when cooled.

Always happy to have my dodgy maths put right, but I may be innocent this time.

My calculation is by weight rather than volume because the regulations specify concentration by weight. I thought it better to do the sums their way.

Also, Phil H isn't trying to make battery acid, he's watering down his acid to stay legal. I'm pretty sure that adding 10kg of water to 2 litres of acid will do the trick and that two 10 litre containers will hold the diluted result.

pgk pgk is right to say our sheds are unlikely to be raided. There would be trouble though if concentrated acid was stolen and traced back to the original owner, especially if it had been used in a crime. It would be ironic to suddenly find yourself in a cell because the police recovered your stuff and noticed you were a crimbo too!

Dave

That's a bit far fetched isn't it? All i ever got was "If you don't know who did it then we're not going to find them" and "Sorry you've been the victim of crime.. your crime number for insurance is xxxx"

pgk

Dave,

I was replying to Phil H1, not you. I did not even read your post, to be quite honest. Procedures in chemistry can be important. Mixing ten lots of acid with one lot of water, in this case, was obviously wrong - he only has two litres of acid and wanted 20 litres of product to dilute further, later.

I gave an example of diluting sulphuric acid that involved about 10 1/2 litres of liquid which provided 10 litres of product. He would likely finish up with less than 20 litres, but at that point, I didn’t know. - I was not prepared to guess or work it out. I’m a chemist, so precision dilutions were more my line of business.

I then gave a good simple idiot-proof plan for achieving 20 litres of product. A practical plan.

BTW, we now have you writing the wrong procedure once more. Always add conc sulphuric to water, never the other way round as you sloppily indicated in your post. Very misleading of you, and could lead to serious personal injury for anyone following your indicated order of operation. ACID TO WATER EVERY TIME (with agitation) is the correct, safe method. The alternative is dangerous.

Bit of confusion here, I thought we where both addressing Phil's later question, which was:

... if there are 2 litres of 95% acid and I mix them 10:1 with water (to be diluted to 30:1 when needed) that would give 2 off legal 10l storage bottles. Is that about right?

I think that's 'about right', noting that it's only necessary to use 10kg of water to render the acid legal. Do you agree?

Dave

WOW ..............

All getting a bit personal now.

It will be handbags at dawn next.

Get me a ticket! Can't wait!

Keith

Thanks very much chaps. I will go on the safe side with the mixing because according to my Rob Roy book - 30:1 is good as a pickling solution - so 10:1 ish is fine for storage.

pgk is sort of right i.e., what army of loons are going to inspect sheds and garages round the country but stranger thinks have happened and these days if a prosecution is easy - the morons will go for it.

My chief concern of course is what happens if I have an accident or worse. I don't want to leave my wife in a 'pickle'. I am joking when I say I won't tell her about the storage - I will and more importantly - how to deal or at least who could deal with all my other tools etc.

Phil H

For heavens sake never ever add water to sulphuric acid. If its a strong acid it will literally blow up in your face.

Thanks for the safety warning Fizzy but I don't think anybody is suggesting doing it the wrong way round.

Phil H