What is the color of the complex ion [Cu(H2O)6]2+?
Practice Questions
Q1
What is the color of the complex ion [Cu(H2O)6]2+?
Blue
Green
Yellow
Red
Questions & Step-by-Step Solutions
What is the color of the complex ion [Cu(H2O)6]2+?
Correct Answer: Blue
Step 1: Identify the complex ion, which is [Cu(H2O)6]2+. This means it has a copper (Cu) ion surrounded by six water (H2O) molecules.
Step 2: Understand that copper in this complex is in the +2 oxidation state (Cu2+).
Step 3: Recognize that transition metal complexes can absorb certain wavelengths of light, which causes electrons to move between different energy levels (this is called d-d transitions).
Step 4: Know that when light is absorbed, the complementary color is what we see. For [Cu(H2O)6]2+, it absorbs light in the red/orange region.
Step 5: Since it absorbs red/orange light, the color we see is blue, which is the complementary color.
