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TBR Ochem II page 71 #89
"How does propanoic acid exist after it has been added to water given it has a pKa of 5.0"?
Okay so if I just ignore all my TBR training, then the correct answer (Less than 1% deprotonated) is easy since pKa of 5.0 means Ka of 10^-5 which means barely any of the acid is deprotonated.
However, I just did the TBR titrations chapter where it was beaten into my head that you should compare the pKa of the substance with the pH of the solution to determine whether the substance is protonated.
Here, since pH = 7.0 which is GREATER than the pKa of propanoic acid, I thought that the propanoic acid should be mostly DEPROTONATED in water.
Can someone reconcile this?
"How does propanoic acid exist after it has been added to water given it has a pKa of 5.0"?
Okay so if I just ignore all my TBR training, then the correct answer (Less than 1% deprotonated) is easy since pKa of 5.0 means Ka of 10^-5 which means barely any of the acid is deprotonated.
However, I just did the TBR titrations chapter where it was beaten into my head that you should compare the pKa of the substance with the pH of the solution to determine whether the substance is protonated.
Here, since pH = 7.0 which is GREATER than the pKa of propanoic acid, I thought that the propanoic acid should be mostly DEPROTONATED in water.
Can someone reconcile this?