Final answer:
CuCl₂ and VOCl₂ are expected to exhibit the same color in solution due to the presence of unpaired d-electrons in their transition metal ions. The correct answer is option C).
Step-by-step explanation:
The pair that is expected to exhibit the same color in solution is CuCl₂ and VOCl₂. Both compounds have transition metals in their formulas, which typically give rise to colorful compounds due to the presence of unpaired d-electrons. Transition metals can undergo electronic transitions between their different d-orbitals.
Resulting in the absorption and emission of specific wavelengths of light, leading to colorful solutions. Copper(II) chloride (CuCl₂) contains a copper(II) ion (Cu²⁺), which has unpaired d-electrons. Vanadium(IV) oxide (VOCl₂) contains a vanadium(IV) ion (V⁴⁺), which also has unpaired d-electrons.
These unpaired d-electrons allow both compounds to absorb and emit light in the visible range, giving them similar colors in solution.