Sunday, November 23, 2008

It's good for your health


The poisonous botulinus organism does not grow in canned vegetables if the pH is less than 4.5. Some investigators (Journal of Chemical Education, 22, 409, 1945) have recommended that in home canning of nonacid foods, such as beans, without a pressure canner a quantity of hydrochloric acid be added. The amount of hydrochloric acid recommended is 25 ml of 0.5 N hydrochloric acid per half-liter jar. Calculate the pH that this solution would have, assuming it originally to be neutral, and neglecting the buffering action of the organic material. Also calculate the amount of baking soda (NaHCO3), measured in teaspoonfuls, that would be required to neutralize the acid after the jar is open. One teaspoon equals 4 grams of baking soda.

by Linus Pauling from General Chemistry

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