pH vs pKa intuition скачать в хорошем качестве

pH vs pKa intuition

Intuitive Thinking about pH & pKa - no fancy math required, just some critical thinking like a molecule @ pH = pKa, there are equal amounts protonated & deprotonated @ a pH below the pKa, you're mostly* protonated @ a pH above the pa, you're mostly* deprotonated For every 1 pH unit difference, there's 10-fold more of one form than the other If pH is within 1 pH unit of pKa, you have lots of each - buffering region If pH is win 2 pH units of pKa, you still have significant amounts of each If pH is ~3 or more pH units away from pKa, it's pretty much "all" in one form Use Henderson-Hasselbalch if you need actual numbers! Caution: Know that the pKa can be highly context-dependent. So, for example, lysine does exist in it its deprotonated form in various locations, which allows it to act as a powerful nucleophile! Also know that the difference between pretty much all and all can sometimes be really important! Especially if you only need a catalytic amount of something. Note: The Henderson-Hasselbalch equation is still really important! It can put actual values to “mostly” and “almost all” but its real power is that it’s also great for other calculations like buffer calculations. Much more on it here: http://bit.ly/phbuffers YouTube:    • Henderson-Hasselbalch equation = where it ...   &    • Avoiding common problems & confusion w/Hen...   more about all sorts of things: #365DaysOfScience All (with topics listed) 👉 http://bit.ly/2OllAB0 or search blog: http://thebumblingbiochemist.com