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Old June 25, 2015   #38
bower
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Quote:
Originally Posted by moray-eel-bite View Post
I know this is an older thread/post, but I wanted to point out that the above calculation doesn't work. pH is a log scale, which means you can't simply add and divide like this. In fact, with the above sample information, the end pH if mixed in equal proportions would be 2.7, not 4.7 as suggested.

-log(0.003981mol/L*.5L + 0.0000001mol/L * 0.5L)= 2.7

Mixing vinegar and water in equal proportions is fine, and will prevent botulism, provided the food stuff itself doesn't have significant buffering capacity/alkalinity.

Cheers,

MEB
MEB, I appreciate the correction ( and I really don't know how to do calculations in log scales). I would like to get this right, and have a correct idea of the pH in different mixtures of vinegar and water.
But is there possibly an error in your calculation?
By this reckoning, a mixture of vinegar and water would end up with a lower pH than the vinegar we started with in the first place..???
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