State the shape of the ozone molecule and estimate the bond angle.

Shape:

Bond angle:

State the hybridization of the central oxygen atom.

In terms of \(\sigma \) and \(\pi \) bonds, describe the two oxygen-oxygen bonds in the Lewis structure.

The two oxygen-oxygen bonds in ozone are in fact of equal length. Deduce why this is the case and how the length of these would compare to oxygen-oxygen bond lengths in hydrogen peroxide, \({{\text{H}}_{\text{2}}}{{\text{O}}_{\text{2}}}\), and in the oxygen molecule, \({{\text{O}}_{\text{2}}}\).

Shape: non-linear / bent / v-shaped / angular;

Bond angle: 117°;

Accept values from 115° to 119° / just/slightly less than 120°.

\({\text{s}}{{\text{p}}^{\text{2}}}\);

one is just one \(\sigma \) and one has one \(\sigma \) and one \(\pi \);

Accept “both bonds comprise one \(\sigma \) and a shared \(\pi \) “/ OWTTE.

delocalization occurs / delocalized \(\pi \)-bond / (has two) resonance structures / it is a resonance hybrid;

length intermediate between \({{\text{H}}_2}{{\text{O}}_2}\) and \({{\text{O}}_2}\) / OWTTE;

Many students scored well on this because, in order that candidates were not too heavily penalised, ECF was applied to the later parts of the question based on the number of electron domains and bonding represented by the Lewis diagram drawn in part (a). Hence, although quite a few students incorrectly tried to reflect the delocalization of ozone in their Lewis structures in part (a), their answers to the later parts of the question were correct. In the final part quite a number of students appeared unable to deduce that hydrogen peroxide contains a single O–O bond.

Many students scored well on this because, in order that candidates were not too heavily penalised, ECF was applied to the later parts of the question based on the number of electron domains and bonding represented by the Lewis diagram drawn in part (a). Hence, although quite a few students incorrectly tried to reflect the delocalization of ozone in their Lewis structures in part (a), their answers to the later parts of the question were correct. In the final part quite a number of students appeared unable to deduce that hydrogen peroxide contains a single O–O bond.

Many students scored well on this because, in order that candidates were not too heavily penalised, ECF was applied to the later parts of the question based on the number of electron domains and bonding represented by the Lewis diagram drawn in part (a). Hence, although quite a few students incorrectly tried to reflect the delocalization of ozone in their Lewis structures in part (a), their answers to the later parts of the question were correct. In the final part quite a number of students appeared unable to deduce that hydrogen peroxide contains a single O–O bond.

Many students scored well on this because, in order that candidates were not too heavily penalised, ECF was applied to the later parts of the question based on the number of electron domains and bonding represented by the Lewis diagram drawn in part (a). Hence, although quite a few students incorrectly tried to reflect the delocalization of ozone in their Lewis structures in part (a), their answers to the later parts of the question were correct. In the final part quite a number of students appeared unable to deduce that hydrogen peroxide contains a single O–O bond.