Zadanie 7b
Wzorowane na: Chemistry HL Paper 2, May 2022, TZ2, pytanie 7(b). Treść, dane i kontekst są zmienione; sprawdzane umiejętności, format i punktacja jak w oryginale.
Darmowe konto pozwoli wrócić do niego później.
Informacja do zadań 7a-7d.
Acrylonitrile, CH2=CH−C≡N, is manufactured on a large scale from propene and ammonia.
Polecenie
(i) Sketch the shape of a sigma (σ) bond and of a pi (π) bond, showing the overlapping orbitals.
Sigma (σ):
Pi (π):
(ii) Identify the number of sigma bonds and the number of pi bonds in one molecule of acrylonitrile.
Sigma (σ):
Pi (π):
(iii) State the hybridization of the carbon atom of the −C≡N group in acrylonitrile.
Sprawdź rozwiązanieUkryj rozwiązanieKlucz i punktacja
Odpowiedź z klucza
(i) sigma: head-on overlap of two orbitals (s–s, s–p or p–p) with the electron density concentrated along the line joining the nuclei ✔
pi: sideways / lateral overlap of two parallel p orbitals, giving electron density in two regions above and below the line joining the nuclei ✔
(ii) sigma: 6 AND pi: 3 ✔
(iii) sp ✔
Schemat punktowania
(i) [1] for each correct sketch; shading is not required and any drawing of overlapping orbitals with the correct geometry is accepted. (ii) both numbers needed. (iii) [1]. The six σ bonds are 3 C–H, 2 C–C and 1 C–N; the three π bonds are 1 in C=C and 2 in C≡N.