Zadanie 2e
Wzorowane na: Chemistry HL Paper 2, May 2026, TZ1, pytanie 2(e). Treść, dane i kontekst są zmienione; sprawdzane umiejętności, format i punktacja jak w oryginale.
Darmowe konto pozwoli wrócić do niego później.
Informacja do zadań 2a-2e.
Rubidium, Rb, is a reactive metal.
Polecenie
(i) Iron, Fe, is a transition element. State two properties typical of transition elements that iron shows, other than the formation of coloured compounds.
(ii) Explain why aqueous solutions containing the hexaaquacopper(II) ion, [Cu(H2O)6]2+, are coloured.
Sprawdź rozwiązanieUkryj rozwiązanieKlucz CKE i punktacja
Odpowiedź z klucza
(i) any two of:
variable oxidation state «e.g. Fe2+ and Fe3+» ✔
high melting/boiling point/hardness ✔
high density ✔
catalytic activity «e.g. iron in the Haber process» ✔
formation of complex ions ✔
high electrical/thermal conductivity ✔
magnetic/paramagnetic behaviour ✔
(ii) any three of:
partially filled d-sub-level «Cu2+ is 3d9» ✔
the d-orbitals are split «into two sets of different energy by the ligands» ✔
light is absorbed as an electron is promoted from a lower to a higher d-orbital «a d–d transition» ✔
the energy gap corresponds to a frequency in the visible region AND the colour seen is the complementary colour of the light absorbed «red/orange absorbed, blue transmitted» ✔
Schemat punktowania
(i) [2] one mark per correct property (any two); accept magnetic/paramagnetic; do not accept partially filled d-orbitals (that is the cause, not a property) or formation of coloured compounds (excluded in the question). (ii) [3] any three of the four marking points (partially filled d-sub-level; d-orbitals split; light absorbed as an electron is promoted between d-orbitals; energy gap in the visible region). Accept 'the colour observed is the complementary colour' for the fourth point only if visible light is mentioned somewhere in the answer.