# Why are sulfate ion and p‐toluenesulfonate (tosylate ion) good leaving groups?

Jan 15, 2015

For example, the $\text{p"K_"a}$ of p‐toluenesulfonic acid is -2.8. The $\text{p"K_"b}$ of its conjugate base, p‐toluenesulfonate ion, is 16.8 — a very weak base.