Question

Consider solutions of the following complex ions. Which solutions would be expected to be colorless and which would exhibit color?

Answer 1

The color of complex ions depends on the electronic configuration of the transition metal ion. Colorless complexes often have a full or empty d subshell, while colored complexes have partially filled d subshells.

Step-by-step explanation:

The color of complex ions in solution is often determined by the electronic configuration of the metal ion. Specifically, transition metal ions with partially filled d subshells generally form colored complexes, whereas ions with a completely empty (d°) or completely filled (d¹°) d subshells are usually colorless. For example, CuI, which has a d¹° configuration, tends to be colorless. In contrast, Cu(NO3)2.5H2O with a transition metal ion that has a partially filled d subshell exhibits color. Similarly, ions such as [Mg(H2O)6]2+, [Al(H2O)6]3+, [Ca(H2O)6]2+, [Sc(H2O)6]3+, and [Zn(H2O)6]2+ are all colorless because they have either fully filled or empty d subshells.

Answer 2

complex ions that would be colorless include

(i) scandium iii

(ii) zinc ii

Complex ions with color include

Copper ii

Iron ii

Iron iii etc

Step-by-step explanation:

Scandium iii and zinc ii are colorless complexes because its 3d level is empty the are sometimes not regarded as a transition element. WHILE

Complex ions containing transition metals are usually coloured this is because of the partly field orbitals which is involved in generating the color in some ways.