Bill Schramm wrote:
> I am sorry, that is not correct. Check your math. Negative numbers > do not have logarithms, but logarithms THEMSELVES can be negative, and > in fact are negative for any (positive) number between 0 and 1. The > log of 0.1 is minus 1, the log of 0.01 is minus 2, etc. The pH is > actually defined as MINUS the logarithm of the hydrogen ion > concentration in moles per liter. So a pH of 7 means that the > logarithm of the hydrogen ion concentration is MINUS 7, or the > concentration itself is ten to the minus seventh power (moles per > liter). Only in extremely strong, concentrated acids will there be > more than one mole per liter. When this is true, the logarithm of the > molar concentration will be positive and therefore the pH will by > definition be negative. The bottle of muriatic acid says 20% > concentration. This would mean that in a liter of acid (1000 grams) > about 200 grams would be HCl. Divide this by the molecular weight of > HCl which is about 36 and you get a little over 5 moles per liter > which would correspond to a pH of minus 0.7 If you want a more > reasonable approximation of stomach acid look up the pH of stomach > acid and dilute accordingly. Example, (I'm not a biologist) if > stomach acid were pH 2, you should dilute the muriatic acid 500 to 1. > > Sorry, you are right. I remember being taught that for logarithms of > numbers below 1, that the exponent part is negative, but the mantissa > is always positive, something I always considered very strange. > > Marshall
