The pKa value of benzene sulfonic acid is approximately -2.8. This value indicates that benzene sulfonic acid is a strong acid, as it has a pKa value lower than that of common strong acids like hydrochloric acid pKa = -6 and sulfuric acid pKa1 = -3 .The acidity of benzene sulfonic acid in different solvents can be affected by the solvent's properties, such as polarity and hydrogen bonding ability. In polar solvents like water, the strong acidity of benzene sulfonic acid is maintained, as the polar solvent can stabilize the charged species formed upon ionization i.e., the sulfonate anion and the hydronium ion . This stabilization leads to a higher degree of ionization and, consequently, a higher acidity.In nonpolar solvents, the acidity of benzene sulfonic acid may be reduced, as these solvents are less capable of stabilizing the charged species formed upon ionization. As a result, the equilibrium between the ionized and non-ionized forms of the acid may shift towards the non-ionized form, leading to a lower acidity in nonpolar solvents.It is important to note that the pKa value is specific to an aqueous solution, and the acidity of a compound can vary in different solvents. However, the pKa value can still provide a general indication of the compound's acidity across various solvents.