Zadanie 8a
Wzorowane na: Chemistry HL Paper 2, November 2024, pytanie 8(a). Treść, dane i kontekst są zmienione; sprawdzane umiejętności, format i punktacja jak w oryginale.
Darmowe konto pozwoli wrócić do niego później.
Informacja do zadań 8a-8b.
A voltaic cell is assembled from a strip of lead, Pb(s), and a strip of copper, Cu(s), each of which dips into a solution of its own nitrate, Pb(NO3)2(aq) or Cu(NO3)2(aq).
Polecenie
The diagram shows the apparatus. The left-hand half-cell is the anode and the right-hand half-cell is the cathode; the electrodes and solutions are not labelled.
State which electrode and which solution are in each half-cell, and state the direction of electron flow in the external circuit. Use section 19 of the data booklet.
Sprawdź rozwiązanieUkryj rozwiązanieKlucz i punktacja
Odpowiedź z klucza
anode (left): Pb electrode AND Pb(NO3)2(aq) / Pb2+(aq) solution
AND
cathode (right): Cu electrode AND Cu(NO3)2(aq) / Cu2+(aq) solution ✔
electrons flow from the anode to the cathode through the external circuit / from left to right through the wire and voltmeter ✔
«E⊖(Pb2+/Pb) = −0.13 V is more negative than E⊖(Cu2+/Cu) = +0.34 V, so lead is oxidized at the anode»
Schemat punktowania
M1: each electrode paired with its own solution, lead at the anode and copper at the cathode; M2: electron flow from anode to cathode through the external circuit, not through the salt bridge or solutions.