But these two groups can gain and lose an H atom, and it happens at a PKA value of around 4.1. So PKA for both of these is around 4.1. Now, once again, your textbook or your teacher might give you slightly different PKA values. And that's because under different conditions, for example, if the temperature is different, these PKA values will be slightly different. So that's okay because this method still works for those values as well. So we have a PK of eight, 4.14.1 and three.