The type of problem highlighted in my recent post is a very serious one and so rather than giving the answer I want to help you discover it for yourself. Hopefully then you will have a wow! or aha! or buggerthat! moment that will help orient you to the importance of semantic tools. Persevere in this and you will see why I rant against PDF, why weak OA does not normally provide high quality semantic documents.
You need to know a very little chemistry and I’ll explain it all below. But first the essence of the problem (relating to methyl chloromethyl ether – you can look it up on WP but it’s not necessary to solve the problem)
In essence the chemical formula as given:
is completely incompatible with the molecular mass as given:
Molecular mass: 80.5
For those who have forgotten high-school chemistry all you need to know is:
- Elements are defined by an unambiguous symbol. Thus “H” means hydrogen, “C” means carbon, “O” means oxygen. You can look up all the information in Wikipedia.
- The count of each element is one, unless subscripted. Elements can be repeated. Thus CH3OH is read as one carbon, three hydrogens, one oxygen and another hydrogen. Adding them up gives one carbon, four hydrogens and one oxygen.
- to get the molecular mass you look up the atomic masses of each element in the Wikipedia entry (or on the Blue Obelisk site) and multiply by the count. The example above (methanol) goes: 1 carbon @ 12 = 12; 4 hydrogens @ 1 = 4; 1 oxygen @ 16 = 16. Add together and the answer is 32 (you can check in Wikipedia). Note that you should round the atomic masses to the nearest 0.5 (my teaser is not a problem of decimal points).
If you do this for the puzzle compound you should discover the problem.
And you’ll see why it bears on PDF, OA, and all the rest.
If we had semantic chemical tools where the information was checked as it was entered this COULDN’T happen. Now for that we need something like a chemical plugin for Word.
Is there a good fairy out there?