TB 6C.19 [ENDORSED]

[Joana Fang 1K]

TB 6C.19

B. Why is HClO2 a stronger acid than ClO? The solutions manual mentions a higher oxidation state; could someone explain the significance of this?

C. Why is HClO2 stronger than HBrO2? The solution says that because Cl is more electronegative than Br, in HClO2, the H-O bond would be more polar. What is the effect of the polarity on the bond that the compound is now stronger? Doesn't polarity make a bond stronger, and thus an acid weaker?

Any help is appreciated :D

[Jonathan Sautter 1J]

So for b) the reason that HClO2 is stronger than HClO is because due to the additional oxygen atoms, which have a higher electronegativity than Cl, the Cl is going to have more of a positive oxidation state/ positive charge. This positive charge is going to repel more stronger the H atom's positive charge than the Cl atom in the molecule with only one oxygen atom because it has a lower positive oxidation state.

For c) HClO2 is going to be stronger than HBrO2 because in both molecules the bond that will break to release the H+ atom is between the O-H. Since Cl is more electronegative than Br, the electrons in O are going to be pulled more strongly toward itself and Cl and thus the shared electrons between the O-H bond are going to leave the H atom more and thus weaken the bond more and make it the stronger acid.