TBR gen chem part II Titration curves review #25

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Mar 19, 2020
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"Venous blood pH is approximately 7.2. Given that pka1 for H2CO3 is 6.4 and pka2 for H3PO4 is 7.1...which of the following relationships is not true about the concentrations of various species in venous blood?"

The answer is that H2PO4-is not in greater concentration than HPO42- in venous blood. I don't understand why this is, since H2PO4- has a pKa of 7.1 and HPO42 has about 12.3.

Can someone explain why that answer is right? It is page 117 #25 if anybody has the book and can help.


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May 25, 2007
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Perhaps this post from the author's office hours will help.

TBR Gen Chem part 2 page 117 Q 25 (from Todd's OH).png
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