Use the example of HCl and HF ionization to indicate that each will donate only one hydrogen ion per molecule. Define these as monoprotic acids. List a few other monoprotic acids. Show using the structural formula why acetic acid is a monoprotic acid. Discuss why the ionizable hydrogen is the one attached to the oxygen which is more electronegative than the carbon. Show why the hydrogen in HF is bonded to the highly electronegative fluorine, creating a polar molecule which allows HF to ionize into an acid. Discuss why benzene, C6H6 is not an acid based on carbon and hydrogen having the same electronegativity.