Zadanie 31
Wzorowane na: Chemistry HL Paper 1, May 2023, TZ1, pytanie 31. Treść, dane i kontekst są zmienione; sprawdzane umiejętności, format i punktacja jak w oryginale.
Darmowe konto pozwoli wrócić do niego później.
Polecenie
A voltaic cell is assembled from the two half-cells below, connected by a salt bridge.
| Half-equation | E⊖ / V |
|---|---|
| Mg2+(aq) + 2 e− ⇌ Mg(s) | −2.37 |
| Cu2+(aq) + 2 e− ⇌ Cu(s) | +0.34 |
Which statement is correct?
A. Anions move from the salt bridge into the magnesium half-cell
B. Anions move from the salt bridge into the copper half-cell
C. Electrons flow in the external circuit from the copper electrode to the magnesium electrode
D. The mass of the copper electrode decreases
Sprawdź rozwiązanieUkryj rozwiązanieKlucz i punktacja
Odpowiedź z klucza
A ✔
«magnesium has the more negative potential, so it is the anode: Mg → Mg2+ + 2 e−; positive charge builds up in that half-cell and anions from the salt bridge move in to balance it. Electrons flow from magnesium to copper, and copper is deposited on the copper electrode, so its mass increases»
Schemat punktowania
One mark for the correct option.