Zadanie 31
Wzorowane na: Chemistry HL Paper 1, May 2024, TZ2, pytanie 31. Treść, dane i kontekst są zmienione; sprawdzane umiejętności, format i punktacja jak w oryginale.
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Polecenie
Zinc lies above nickel in the reactivity series. A voltaic cell is made from a zinc electrode in Zn2+(aq) and a nickel electrode in Ni2+(aq). The electrodes are connected by a wire with a voltmeter, and the two solutions are connected by a salt bridge. Which statement is correct about the cell?
A. Electrons flow from the nickel electrode to the zinc electrode in the wire
B. Positive ions in the salt bridge flow towards the zinc half-cell
C. The zinc electrode is the cathode
D. The mass of the nickel electrode increases
Sprawdź rozwiązanieUkryj rozwiązanieKlucz i punktacja
Odpowiedź z klucza
D ✔
«zinc is the more reactive metal, so it is oxidized at the negative electrode (anode): Zn → Zn2+ + 2 e−; electrons flow through the wire from zinc to nickel, where Ni2+ is reduced (cathode): Ni2+ + 2 e− → Ni, so nickel is deposited and the electrode gains mass; negative ions flow through the salt bridge towards the zinc half-cell»
Schemat punktowania
One mark for the correct option.