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Video transcript

the pH of the soft drink is 3.37 after the addition of the potassium sorbate which species the sorbic acid or the sorbate ion has a higher concentration in the soft drink justify your answer so this is related to the question we've been doing because the sorbate ion this is this is what happens when you put potassium sorbate and it disassociates in a solution so the concentration of the sorbate ion is the same thing as the concentration one way to think about it saying is is is going to be the same as the concentration of your potassium sorbate and so if we're thinking about if we're thinking about titrating potassium sorbate which we've been doing in the last several parts of the problem at what point do you have an equal concentration of potassium sorbate and and sorbic acid well you have equal concentrations at the half equivalence point we mark that out when we we figured it out in the last few parts of this problem and the half equivalence point happened at a pH of four point we actually figured it out before four point seven seven so we could say we could say half equivalence point half half equivalence quillin's point of titration of potassium sorbate potassium sorbate with hydrochloric acid happens happens at a pH of let me write that pH of four point seven seven and that's the point at which you have equal concentrations of so we can put this in parentheses can be viewed as point where we have equal concentrations concentrations of of c6h 7:02 - and the sorbic acid h c 6h 702 pH of 3.77 pH of 3.37 is lower and will thus or we could say will happen beyond half equivalence point beyond half e equivalence gravel its point so concentration of the sorbic acid is higher so concentration asian of sorbic acid h c 6h 702 is higher when you're starting off if you're doing a titration your your concentration of potassium sorbate it'll be higher then you keep titrating it keeps reacting with the hydrochloric acid you get to the half equivalence point where these two things are going to have equally concentrations and you if you keep titrating it well then you're gonna become more acidic and you're going to have a higher concentration of the sorbic acid and so one way to think about actually underlying that whole part so concentration of sorbic acid is higher that's the main thing that they're they're asking for but the way to think about this soft drink is something it might have not obviously people aren't sitting there and titrating every soft drink but you could kind of view this soft drink as well and got to that point after a theoretical titration that got us past the high past the past the half equivalence point and so therefore most of of our the things that we care about as in the form as in this acid form versus the conjugate base most of the the sorbic acid isn't it is in its acid form or I guess you could say the other way most of the sorbate has become the conjugate acid
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