Zadanie 23
Wzorowane na: Chemistry SL Paper 1, November 2022, pytanie 23. Treść, dane i kontekst są zmienione; sprawdzane umiejętności, format i punktacja jak w oryginale.
Darmowe konto pozwoli wrócić do niego później.
Polecenie
Molten lead(II) bromide is electrolysed using inert graphite electrodes connected to a DC power supply. Bromine forms at one of the electrodes. Which row is correct for the electrode where bromine forms?
A. Anode; positive electrode; electrons leave this electrode through the external circuit
B. Anode; negative electrode; electrons leave this electrode through the external circuit
C. Cathode; negative electrode; electrons enter this electrode through the external circuit
D. Anode; positive electrode; electrons enter this electrode through the external circuit
Sprawdź rozwiązanieUkryj rozwiązanieKlucz i punktacja
Odpowiedź z klucza
A ✔
«bromide ions are oxidized, 2 Br− → Br2 + 2 e−, and oxidation occurs at the anode. In an electrolytic cell the anode is connected to the positive terminal of the power supply, so it is the positive electrode, and the electrons released there leave through the external circuit towards the cathode. The negative cathode, where electrons enter, is where lead forms»
Schemat punktowania
One mark for the correct option.