Final answer:
Cations indeed affect the color of a solution, as their electronic configurations influence light absorption properties. This is particularly relevant for transition metal ions, where the presence of certain species nearby changes electronic transitions and thus, the observed color.
Step-by-step explanation:
When considering whether the cation in solution affects color, the answer is Yes, cations can affect the color of a solution. This is because cations, especially transition metal ions, can have different electronic configurations that influence the light absorption properties of the compounds they form. For instance, cobalt salts containing Co²+ ions demonstrate changes in color based on the species surrounding the cobalt ion and the presence of water molecules in the coordination sphere around the central cobalt ion. These changes affect the relative energies of the d orbitals that electrons transition between, altering the color of light absorbed. A d¹⁰ copper(I) complex like CuI is usually colorless, indicating a full d orbital and no transitions to absorb light. Conversely, a d⁹ copper(II) complex such as Cu(NO3)2.5H₂O is brightly colored because the presence of an empty d orbital allows for electronic transitions that absorb certain wavelengths, and the reflected light yields the compound's observed color.