Field of Science

Ant-acids

I'm teaching general chemistry this semester. Acids and bases are currently on our agenda, in particular how to assess the strength of an acid based on its molecular structure. When dissolved in water, strong acids, such as hydrochloric acid (HCl) or sulfuric acid (H2SO4) always transfer their protons (H) to water. For example: HCl + H2O → Cl + H3O+. Weak acids result when only some acid molecules transfer their protons to water. Organic acids, containing only carbon, oxygen, hydrogen and nitrogen, are generally weak acids. The archetypical weak organic acid is acetic acid, better known as vinegar: CH3COOH. It's not the simplest organic acid, that would be formic acid: HCOOH.

Formic acid was first characterized in the late 17th century. Naturalists had observed that the vapors emitted by ant hills were acidic (using the equivalent of litmus paper), and in 1671 John Ray extracted the pure acid by distilling the crushed remains of red ants. Formica is Latin for ant, hence the name translates pretty literally as "ant acid". Formic acid is at least partially responsible for the sting in bee stings, ant bites and stinging nettles.

Even though chemists call formic acid weak, a 0.10 M solution has a pH of 2.4 (for comparison's sake, the same concentration of HCl has a pH of 1.0).


I remember find ants all over my Formica counter in my post-doc days. Does the ubiquitous counter-top material have any connection to ants? Apparently not. It was originally created as a substitute for mica insulators. For mica....

8 comments:

  1. My cats love rolling on the floor where I've crushed invading ants [every spring we get invaded through our back door]. I'm sure they are attracted to formic acid. It must have a nice smell for a cat.

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  2. There may be more of a connection between formica and formaldehyde.

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  3. There's no etymological connection between formica and formaldehyde. Formica was originally made as an electrical insulator in the early 20th century as a substitute "for mica"; formaldehyde is derived from formic acid (both etymologically and chemically).

    Interestingly, formica (which does not release formaldeyde) is used to prevent the outgassing of formaldehyde from particle board.

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  4. Would bees then be attracted to ant hills or nests?

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  5. Would bees then be atracted to ant hills or nests?

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  6. mudd...are bees attracted to formic acid? I don't know.

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  7. Cool blog you got here. It would be great to read more concerning this matter.
    BTW check the design I've made myself Young escorts

    ReplyDelete
  8. Does the prescence of ants (huge ant colony) in the soil have any effect on the PH balance?

    ReplyDelete


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