Zadanie 2c
Wzorowane na: Chemistry HL Paper 2, May 2023, TZ2, pytanie 2(c). Treść, dane i kontekst są zmienione; sprawdzane umiejętności, format i punktacja jak w oryginale.
Darmowe konto pozwoli wrócić do niego później.
Informacja do zadań 2a-2d.
Atmospheric pollutants include oxides of sulfur, which cause acid deposition, and ozone, which is formed in photochemical smog.
Polecenie
The two O-O bonds in ozone have the same length, 1.28 × 10−10 m. For comparison, an O-O single bond is 1.48 × 10−10 m long and an O=O double bond is 1.21 × 10−10 m long.
(i) Suggest what the bond lengths indicate about the structure of ozone.
(ii) Predict the O-O-O bond angle in ozone.
Sprawdź rozwiązanieUkryj rozwiązanieKlucz i punktacja
Odpowiedź z klucza
(i) ozone has resonance structures / the bonds are equivalent with a bond order between 1 and 2 «about 1.5»
OR
electrons are delocalized over both O-O bonds ✔
(ii) 110 - 119° «actual value 116.8°; three electron domains with one non-bonding pair, so the angle is slightly less than 120°» ✔
Schemat punktowania
(i) [1] for resonance or delocalization, or equivalent bonds of intermediate order; do not accept a statement that only restates that the bonds are the same length. (ii) [1] for any value in the range 110 to 119°, or for a statement that the angle is slightly less than 120° because of the non-bonding pair; 120° and 109.5° score zero.