Question

I'm reading through an MCAT Chemistry book and it keeps referring to HClO as a weak acid. I'm confused why this would be the case.

Here's my logic:
HCl is a strong acid. An electronegative atom such as oxygen should pull electron density away through induction and decrease the pKa of HCl. Therefore, wouldn't it even be an even stronger acid now?

Why am I wrong? Thank you

Answer 1

the dissociation of HClO happens as shown in following reaction,

HClO ---> H⁺ + ClO^-

in ClO^- ion oxygen is more electronegative element than chlorine and an electron withdrawing group too. When oxygen is attached to chlorine atom to form an anion, the negative charge on oygen gets dispersed adjacent to chlorine and hence provides stability to the anion.

As a result HClO dissociates but not as strongly as HCl does. i.e. less number of dissociations leads to less protons in solution and hence lesser acidity(weaker acid) than HCl.