Zadanie 13a
Wzorowane na: Chemistry HL Paper 3, May 2023, TZ1, pytanie 13(a). Treść, dane i kontekst są zmienione; sprawdzane umiejętności, format i punktacja jak w oryginale.
Darmowe konto pozwoli wrócić do niego później.
Polecenie
A direct ethanol fuel cell has an acidic electrolyte. At the anode, ethanol is oxidized to carbon dioxide gas. At the cathode, oxygen is reduced to water.
Write equations for the half-reaction at the anode and the half-reaction at the cathode, and the overall equation for the cell.
Anode:
Cathode:
Overall equation:
Sprawdź rozwiązanieUkryj rozwiązanieKlucz i punktacja
Odpowiedź z klucza
Anode: C2H5OH(l) + 3 H2O(l) → 2 CO2(g) + 12 H+(aq) + 12 e− ✔
Cathode: O2(g) + 4 H+(aq) + 4 e− → 2 H2O(l) ✔
Overall: C2H5OH(l) + 3 O2(g) → 2 CO2(g) + 3 H2O(l) ✔
Schemat punktowania
M1: anode half-equation, balanced for atoms and charge. M2: cathode half-equation. M3: overall equation with the electrons cancelled; award M3 for an overall equation that is consistent with the student's own half-equations (ECF) if the electrons cancel. Accept multiples of the equations and 3 O2 + 12 H+ + 12 e− → 6 H2O for the cathode.