Topic 13

How is color produced in transition metal complexes?

• Light is absorbed when electrons are promoted between split d-orbitals.

• Light is emitted when electrons fall between split d-orbitals.

• Light is absorbed when electrons escape from the complex.

• Light is emitted when the complex returns to ground state.

Part of the spectrochemical series is shown for transition metal complexes. I−< Cl− < H2O < NH3 Which statement can be correctly deduced from the series?

• H2O increases the p–d separation more than Cl−.

• H2O increases the d–d separation more than Cl−.

• A complex with Cl− is more likely to be blue than that with NH3.

• Complexes with water are always blue.

Which best explains why transition metal complexes are colored?

• As electrons return to lower energy levels, light of a certain color is emitted, and the complementary color is observed.

• As electrons return to lower energy levels, light of a certain color is emitted, so the complex appears to have the same color.

• As electrons are promoted to higher energy levels, light of a certain color is absorbed, and the complementary color is observed.

• As electrons are promoted to higher energy levels, light of a certain color is absorbed, so the complex appears to have the same color.

Tags

NGSS.HS-PS4-1

Which factor does not affect the color of a complex ion?

• temperature of the solution

• identity of the ligand

• identity of the metal

• oxidation number of the metal

Which electrons are removed from iron (Z = 26) to form iron(II)?

• two 3d electrons

• two 4s electrons

• one 4s electron and one 3d electron

• two 4p electrons

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2

What is the oxidation state of the metal ion and charge of the complex ion in [Co(NH3)4Cl2]Cl?

• A

• B

• C

• D

Which is correct for the complex ion in [Fe(H₂O)₅Cl]SO₄?

• A

• B

• C

• D

Which complex has the greatest d orbital splitting?

• A

• B

• C

• D

Which statement is correct?

• [CoCl₆]^3– absorbs orange light.

• The oxidation state of cobalt is different in each complex.

• The different colours are due to the different charges on the complex.

• The different ligands cause different splitting in the 3d orbitals.

Tags

NGSS.HS-PS4-3

What is the charge on the iron(III) complex ion in [Fe(OH)₂(H₂O)₄]Br?

• 0

• 1+

• 2+

• 3+

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2