Acids, bases and carbonates

[richardh08]

Prompted by a recent discussion on the topic, I've written this: http://www.pyrobin.com/files/Acids%20and%20bases.pdf

My intention is that it should be interesting, regardless of anyone's level of knowledge of chemistry. No doubt you will let me know whether I have succeeded or failed!

Written by a physicist, to whom chemistry is just a side-branch of reality

[Pyro-Gear]

Fascinating I got a third of the way through and thought turn the TV off and study the file with no distractions! Later, one thing I would say is sign it and add copyright to pyro-gear.co.uk, outstanding piece of work Richard.
I will be going through the whole file later as I expect some others will be.

[Tyvole]

Thank you very much Richard. I struggled a little and had to re-read some parts, but that made a good deal of sense. I could have done with a teacher like you when I was at school. Chemistry always fascinated me, but somehow, it never 'clicked'. My persistent feeling since then has been that this was down to the teaching...

One question - is OH- called a hydroxyl ion?

P.s. I believe I spotted a minor error (don't forget that I'm a technical writer/editor by trade!). I think you have an H+ missing from this paragraph:
"All carbonates, whether soluble or not, are attacked by acids. For example , if you mix a solution of sodium carbonate with dilute hydrochloric acid, you get a mixture of Na+, CO3
--, H+ and Cl- ions. Since carbonic acid is weak, some of the [H+] will combine with the CO3
-- ions to form un-dissociated carbonic acid:"

Thanks again, this article was very helpful of you.

[richardh08]

Yes, Tyvole, it's a hydroxyl ion. And well done for spotting the deliberate (not!) typo. It's funny how long you can stare at a piece of text and not see the obvious - especially when you have written it yourself; you know what it says!

School chemistry teachers - mine was good but boring. Everything is black and white at that level; bonds are either covalent or ionic, whereas in reality there is a gradation from one extreme to the other. My approach is to try and understand the mechanisms that make things happen the way they do. I hope some of that rubs off on others.

The one thing I'm not entirely happy with is, funnily enough, one of the discussion points that prompted me to start writing this article, and that is the role of boric acid in pyro mixtures. I started out by saying it was pointless to add boric acid to any mix containing carbonates but then I had doubts and tried it out. Boric acid does release CO2 when mixed with sodium carbonate solution, but the reaction is slow and you have to look quite hard to see the tiny stream of bubbles. I then tried it with strontium carbonate and found that this reaction is veeeery slow. Heating the water to hand-hot speeded things up a bit, but it's nothing like as violent as I had originally assumed. Hence my toned-down text.

Boric acid is a very weak acid. I measured the pH of a saturated solution this morning and it turned out to be around 5.5. Bear in mind that the acid in your stomach has a pH of about 1 or 2.

I'll be applying a few tweaks to the document later today, in response to the comments I have received.

[davidg]

Well written,easy to understand.

Thank you for this info.

[Aardvark]

Will definitely give it the concentration it deserves when I get a chance. My experience of Chemistry was extremely similar to Tyvoles; Extremely interested in it... but not the person teaching it.

[Pyro-Gear]

Will definitely give it the concentration it deserves when I get a chance. My experience of Chemistry was extremely similar to Tyvoles; Extremely interested in it... but not the person teaching it.

My chemistry teacher was I complete Nutter extremely interested in pay back, IE 10 number 6 would get you the information you needed and chemicals, quinidine nitrate being a favourite of mine at the time, he was a hippy type very sarcastic stunk of cigarettes or other controlled substances but a fantastic individual , I remember one time in registration he approached me asking for a pack of cigarettes I asked why and his response was you have 8 black marks this month for non-attendance, the packet was handed over! And a mix of potassium permanganate and ammonia was left on his black board duster for the morning.

[Aardvark]

Now that's teaching!!! Where have they all gone... I fear that I've grown up (not quite) in a very boring time.

[Niall]

"Written by a physicist, to whom chemistry is just a side-branch of reality"

Excellent, perhaps you could take a look at this growth on my knee! It's nice to have a GP on the page.



Chemistry - that's nice, but it isn't Physics.....

[richardh08]

But everything is physics so, logically, that must include chemistry

[Niall]

Yes, you are right, EVERYTHING is physics, chemistry is cute, biology is fun and computing is easy.

Law is written down already. Engineering is physics, so they just need to be grateful. Being a Doctor of medicine is Biology, which relies on chemistry, which only happens because of the physics that do not falter in the way a molecule might.

Except for mathematics, the realm of the gods, who don't exist and are conjured up to solve problems in a way that wouldn't have occurred without physics for humans to exist and invent them as an explanation, prior to physics, where the numbers mean something, which keeps the mathematicians in a job. Prior to physics maths did not occur.

What discipline is pure without physics?

[Tyvole]

Catfish noodling, maybe? Nah, even that probably depends on water temperature, flow rate...

[Niall]

The basic principle of Physics:

1. Does it or doesn't it?

2. Why?

3. What can I do to predict an outcome?

4. Was I right?

5. If inkey$=n goto 1; If inkey$=y then print 'Collect Nobel Prize' then goto 1.

[Tyvole]

"inkey$"?
Showing your basic age there buddy!

[Pyro-Gear]

Or possibly an increase in estragon levels!

[coalman]

Hmm looking up the thread I've never come across KMnO4 + NH3OH - my teachers let me down on that one. They were concentrating on another strong coloured substance I guess!

[richardh08]

Hmm looking up the thread I've never come across KMnO4 + NH3OH - my teachers let me down on that one. They were concentrating on another strong coloured substance I guess!

Ken and I have chatted about this. It wasn't KMnO4

[coalman]

Interestingly ammonium permanganate does appear to be friction sensitive but can't be made that way. Not would I make it - it looks a bit dodgy.