h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

I must say that as a professional chemist I find the insistence these days in schools of giving silly names to simple and well known chemicals a bit pointless and irritating.

I've never met a chemist at either undergraduate or PhD level, let alone higher up in the chain who would *ever* refer to these things as anything othe than alcohols. Similarly, ask a passerby if they've heard of an alkanol or an alcohol and see what answer you get.
In fact this is the first time I've ever seen them referred to by this name myself.
Please be aware by the way that this is no way a criticism of your entry.

They teach people this stuff at GCSE and A level and then when you go onto more advanced stuff it's been a pointless exercise and probably more confusing than anything else.

Similar stuff with acids and aldehydes/ketones.

I use formaldehyde in my lab, not methanal. I use acetic acid (as it is still sold on the bottle) no ethanoic acid. Why are such things taught at school and then never seen again? Why bother with it, they should teach the real names at school.

I personally expect that, just as bicarbonates are now often called 'hydrogencarbonates', alcohols will become increasingly known as 'alkanols', carboxylic acids as 'alkanoic acids', aldehydes as 'alkanals' and ketones as 'alkanones', so titled the articles appropriately, mentioning the far more common names early on in each article. I could be wrong, and the names may fade to obscurity, in which case the articles should be retitled.

RhoMuNuQ

I also suspect it is part of a deliberate plot to change what is regarded as the common/proper name. The same strategy has been used before in other areas when the previous naming scheme was found to be unhelpful for good reason. Old people die off you know and their ideas/conventions with them. I can't quite see the term "alcohol" disappearing completely for a long while though!

Oh it is a deliberate plot. The trouble is - *nobody* calls them alcohols except teachers at school.
As I said - I've never heard the term alkanol before and I am still a relatively young chemist .

When Aldrich who supply almost all the chemicals used in laboratiries still sell acetic acid, formaldhyde etc then it is a little silly to teach children names that to all intents and purposes don't exist outside the classroom.

Besides, these names are really for incredibly trivial organic chemicals and so it's all a bit pointless. The vast majority of organic chemicals contian multiple functional groups and so do not fit nicely into *any* of the newly name classes of compounds.

What is unhelpful about calling something an alkanal instead of an aldehyde anyway? What's the difference except a name? In the end you still have to remember it and if you have trouble with that you really should consider a career outside chemistry

As a retired person I don't have to look for a career at all. I never really had trouble with the various chemical names. I did draw the line at some of the biological jargon which seemed to be there just to prevent people from thinking about what they were actually saying. It was quite clear from the way some people used the words that they were unaware of the basis of them and the implications of them.

On the laboratory ordering side, you could try thinking of it as an intelligence test with the newbies as the rats. If they manage to order/fetch the right bottle then they are kept on. Something is needed to stream the holders of new de-valued exam grades after all.

How true.

Jargon does have purpose but yes, biochemists seem to have leapt most enthusiastically onto the jargon tree. You do need a lot of it though as sentences in ''biochemist" would become truly unintelligible without it.

I was going to ask how to pronounce the odd new word, but if noone uses it, I don't know if I will.

Al-can-ol

Put it this way, I was pouring threw one of the newest undergraduate level text books on organic chemistry yesterday - in its index it has a section on 'alcohols' followed directly by a section on 'aldehydes'
Hardly shows much of a trend towards the new now does it
This book was first published in 2001.

Thank you Orcus. I suppose if one drinks a tall forty from a bottle, it will still remain an al-can-ol solution. Pity I don't know any pubs where I can get a free drink for knowing this.

If you add more -Hs to an unsaturated carbon chain, it changes to a different alk-, but it seems if you add X or Y it does not (this could be wrong, I am speculating from what I am reading here).

If you add more than one -OH group, does it remain an alcohol? Do you need to number mark it?

You mean like 1,1,1-trichloro-ethane. I don't recall coming across a 1,2-ethanol say.

I've just noticed that only one example is drawn out rather than starting at methanol and possibly going as far as propanol.

I've also noticed that quite a strong feeling of something being missing at the end - the methanol to methanoic acid reaction equation. The other examples have equations. It wouldn't have been that much effort to add it but perhaps it appears in one of the other articles (in which case there could be a link to that).

Even with the equation it feels a little as though it tails off without a "conclusion". It could mention the drinks thing as a funny PS I suppose - drink ethanol not methanol. There's already a diagram and therefore some sort of article on that but I don't think it was an appropriate one.

"If you add more -Hs to an unsaturated carbon chain, it changes to a different alk-, but it seems if you add X or Y it does not (this could be wrong, I am speculating from what I am reading here)."

No you are correct. If an alkane has say a chlorine atom (as X) then it becomes an alkyl halide. Ethyl chloride for example is CH3CH2Cl

"If you add more than one -OH group, does it remain an alcohol? Do you need to number mark it?"
Er, yes...ish. You may have heard of ethylene glycol (anti-freeze) this is know as a diol because it has two alcohol groups. It's systematic name is ethane-1,2-diol so yes you *do* have to number mark it. For longer chain versions there are no longer trivial names such as ethylene glycol or glyceral (propane-1,2,3-triol) and so you must use the numbering system.
For example
CH3CH(O)CH2CH2CH2CH(OH)CH3
is heptane-2,6-ol
Convention says you keep the numbers as low as possible.

*whispers* The story doesn't end here. Some carbon atoms in such molecules have four *different* substituents on them and because they are arranged in a tetrahedron around each such carbon atom then there are two such arrangements possible. This is a type of isomerism (isomers are molecules with the same formula but with different structures) and each of these atoms is assigned a configuration according to a set of rules giving the different groups 'priority' over other.
As you can imagine, this is a little complex for the current set of articles.

oops

"For example
CH3CH(O)CH2CH2CH2CH(OH)CH3
is heptane-2,6-ol"

no heptane-2,6-diol

I saw that! You also forgot the H in the first (OH). But we knew what you meant really.

I'd forgotten anti-freeze. Nasty stuff. Actually most/all these hydrocarbon chain molecules are pretty toxic to me (allergies).

Isomerism is well out of the scope of that article.

PS I'm sure we usually called those mirror isomers enantiomorphs in my day.

PPS What about the zero carbon -ol and -diol. (H-O-H and H-O-O-H)

enantiomers

In fact my compounds as drawn (or if drawn correctly in fact ) would be a racemic pair of diastereoisomers - but I'm sure you knew that alreay

Ah, i see you know about the deadly contaminant of water - dihydrogen monoxide.
The other is of course the famous Domestos OX, the Bleach that doesn't smell of bleach

ahem.

"enantiomers"

Yes, that's yet another variation. You'd think they might have managed to stick to just one name for the concept. I always thought the use of isomer (or even stereoisomer) was a bit risky outside maths. I found some chemistry people kept accidentally using isotope instead!

Thanks!

Now I see the oddness of chemists, the original names for things seem to be best.

Similar to the use in universities and labs of the old names e.g. acetic acid, formaldehyde etc. is the use of units.
In A-Level it was drilled into us to have all concentrations in mol.dm-3(sorry about the lack of superscript), or else you lose a terrible amount of marks. However, on arriving at university, everything is measured in g/L or mol/L! And as far as volumes go, it was drilled into us to use ml, whereas in uni everything, including the burettes, is in cm3.

Of course this isnt too much of a hassle, but I just find it funny and slightly silly how in A-Level it was so extremely stressed that you MUST us the S.I. units and nomenclature because thats how its done by grown-up scientists EVERYWHERE.

In publications you must use SI units now.

I may write mL in my lab book but in a publication it must be in cm3. Same for mol dm-3

In practice in the lab, molarity by far the most common concetration used but I find that solutions in percentages are the most convenient to make up - which is why we use it.
The percentage is essentially a percentage concentration weight for weight and since the density of water is 1 then 100g = 100 ml (cm3 )

Hence a 10 % solution of sodium hydroxide is 10 g sodium hydroxide in 100g water or 10 g per 100 ml.

Now to do that in molarity terms is much more complicated.

In publications you must use SI units now.

I may write mL in my lab book but in a publication it must be in cm3. Same for mol dm-3

In practice in the lab, molarity by far the most common concetration used but I find that solutions in percentages are the most convenient to make up - which is why we use it.
The percentage is essentially a percentage concentration weight for weight and since the density of water is 1 then 100g = 100 ml (cm3 )

Hence a 10 % solution of sodium hydroxide is 10 g sodium hydroxide in 100g water or 1g per 100 ml.

Now to do that in molarity terms is much more complicated.