When phenol is sulphonated by fuming sulfuric acid at a lower temperature, the ortho product is the major whereas at higher temperature the para product is formed as the major.
Why does this happen, because looking at the reaction mechanism, it appears to me that para should always be the major.
Is it the kinetic control vs thermodynamic control effect?? If yes, then why is para thermodynamically more stable and ortho kinetically faster??