Zadanie 22
Wzorowane na: Chemistry SL Paper 1, November 2024, pytanie 22. 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 constructed from a half-cell of metal A in a solution of A2+ ions and a half-cell of metal B in a solution of B2+ ions. The half-cells are joined by a salt bridge and an external wire. Metal B is the more reactive metal.
What happens when the cell produces an electric current?
A. Electrons flow through the external wire from the A half-cell to the B half-cell.
B. Positive ions in the salt bridge move towards the B half-cell.
C. The concentration of A2+ ions increases.
D. The mass of the A electrode increases.
Sprawdź rozwiązanieUkryj rozwiązanieKlucz i punktacja
Odpowiedź z klucza
D ✔
«the more reactive metal B is oxidized at the anode (B → B2+ + 2 e−) and the electrons flow through the wire from B to A; at the cathode A2+ + 2 e− → A, so metal is deposited on the A electrode, its mass increases and [A2+] decreases; positive ions in the salt bridge move towards the cathode, the A half-cell»
Schemat punktowania
One mark for the correct option.