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Title: What is the ratio of the concentration of benzoic acid to the concentration of benzoate ion in food? Post by: ripp2373 on Apr 15, 2013 Sodium benzoate (NaC7H5O2) is used as a food preservative. The Ka of benzoic acid is 6.46 x 10^ -5M. What is the ratio of the concentration of benzoic acid to the concentration of benzoate ion in a food with pH=3.00?
Title: What is the ratio of the concentration of benzoic acid to the concentration of benzoate ion in food? Post by: rellyma23 on Apr 15, 2013 Are you OK with using the Henderson-Hasselbalch equation? If so,
first calculate pKa for benzoic acid: pKa = - log Ka The H-H equation is: pH = pKa + log [base]/[acid] In this problem, you are asked to calculate the ratio of acid to benzoate. When you solve the H-H equation for the log term ratio, you will need to take 1/_____. Message me if this doesn't make sense...I'll try again tomorrow. |