Question 21M.2.HL.TZ1.7

✔

Accept any combination of lines, dots or crosses to represent electrons.

Do not accept structures that represent 1.5 bonds.

both equal ✔

delocalization/resonance ✔

Accept bond length between 121 and 148 pm/ that of single O−O bond and double O=O bond for M1.

bond in O₃ is weaker
OR
O₃ bond order 1.5/< 2 ✔

Do not accept bond in O₃ is longer for M1.

lower frequency/longer wavelength «UV light» has enough energy to break the O–O bond in O₃ «but not that in O₂» ✔

Accept “lower frequency/longer wavelength «UV light» has lower energy”.

${\text{CCl}}_{\text{2}}{\text{F}}_{\text{2}}{\text{(g) →∙CClF}}_{\text{2}}\text{(g) Cl}\bullet \text{(g)}$ ✔

${\text{Cl•(g)+O}}_{\text{3}}{\text{(g)→O}}_{\text{2}}\text{(g)+ClO•(g)}$
AND
${\text{ClO∙(g)+O}}_{\text{3}}{\text{(g)→2O}}_{\text{2}}\text{(g)+Cl}\bullet \text{(g)}$ ✔

Do not penalize missing radical.

Accept:for M2:
${\text{Cl∙(g) + O}}_{\text{3}}{\text{(g) → O}}_{\text{2}}\text{(g) + ClO}\bullet \text{(g)}$
AND
${\text{ClO∙(g) + O(g) → O}}_{\text{2}}\text{(g) + Cl}\bullet \text{(g)}$