Zadanie 24
Wzorowane na: Chemistry SL Paper 1A, May 2026, TZ3, pytanie 24. Treść, dane i kontekst są zmienione; sprawdzane umiejętności, format i punktacja jak w oryginale.
Darmowe konto pozwoli wrócić do niego później.
Polecenie
Two acid-base equilibria are shown.
Equation 1: HCN(aq) + H2O(l) ⇌ CN−(aq) + H3O+(aq)
Equation 2: NH3(aq) + H2O(l) ⇌ NH4+(aq) + OH−(aq)
Which option correctly describes the role of water in each forward reaction?
A. In equation 1 water behaves as a Brønsted-Lowry acid; in equation 2 water behaves as a Brønsted-Lowry base
B. In both equations water behaves as a Brønsted-Lowry acid
C. In both equations water behaves as a Brønsted-Lowry base
D. In equation 1 water behaves as a Brønsted-Lowry base; in equation 2 water behaves as a Brønsted-Lowry acid
Sprawdź rozwiązanieUkryj rozwiązanieKlucz CKE i punktacja
Odpowiedź z klucza
D ✔
«in equation 1 water accepts a proton from HCN and behaves as a Brønsted-Lowry base; in equation 2 water donates a proton to NH3 and behaves as a Brønsted-Lowry acid, so it is amphiprotic»
Schemat punktowania
1 mark for the correct option.
Komentarz
Water is amphiprotic; its role follows from whether it gains or loses a proton in the reaction written.