Zadanie 27
Wzorowane na: Chemistry HL Paper 1A, May 2026, TZ3, pytanie 27. Treść, dane i kontekst są zmienione; sprawdzane umiejętności, format i punktacja jak w oryginale.
Darmowe konto pozwoli wrócić do niego później.
Polecenie
The reaction between nitrogen dioxide and fluorine has the overall equation:
2 NO2(g) + F2(g) → 2 NO2F(g)
The reaction follows the energy profile shown:
Two mechanisms are suggested:
| Step | Mechanism X | Mechanism Y |
|---|---|---|
| 1 | NO2 + F2 → NO2F + F (slow) | NO2 + F2 → NO2F2 (fast) |
| 2 | NO2 + F → NO2F (fast) | NO2F2 + NO2 → 2 NO2F (slow) |
Which suggested mechanism is consistent with the energy profile?
A. X
B. Y
C. Neither X nor Y
D. Both X and Y
Sprawdź rozwiązanieUkryj rozwiązanieKlucz CKE i punktacja
Odpowiedź z klucza
A ✔
«the first activation energy is the larger one, so the first step is the slow, rate-determining step; mechanism X has a slow first step and a fast second step, whereas in mechanism Y the second step is slow, which would give a higher second hump»
Schemat punktowania
1 mark for the correct option.
Komentarz
Both mechanisms add up to the overall equation, so the slow step is what distinguishes them.