Question 3.85 b

[Adriana Juarez 1]

For this question it asks us to place the following molecules in order of decreasing bond length (S02, S03, and SO3 2-).

If the bond order for SO2 is 1.5 and the bond order for SO3 is 1.33 (4/3), then why does the book say that these two molecules have equal bond lengths in the solutions manual?

My understanding was lower bond order means a longer bond length.

[Chem_Mod]

Hey Adriana, I believe the book is just referring to experimental data for that statement. In the actual solution, they provide you with SO₃^2- > SO₂ ~ SO₃. I think they are just implying that the small difference in bond order (1.33 vs 1.5) will not have a huge effect on bond length.

If you were trying to qualitatively determine the order, your approach would be perfectly logical. They are just using experimental data and that is why they were being so specific.

[Adriana Juarez 1]

Oooh okay that makes sense. Thank you!

[Michelle Nwufo 2G]

Can someone explain why so32- has a greater bond length than so2-?