The pKa value is a crucial parameter used to determine the acid strength of a molecule. It is determined by calculating the negative base-10 logarithmic value of the acid dissociation constant of the molecule. This value provides a measure of how much the acid dissociates in solution, and hence, its strength. The higher the value of pKa, the lower the extent of dissociation of the acid in solution. Based on this information, you are asked to predict the pKa value of a given molecule.