Question

bronze analysis
wavelength of maximum absorbance
the blue copper(ii) ions interact with the
light by reflecting blue back toward our
eyes.
consider the color wheel below.
what wavelength range should the
inspector set the spectrophotometer to
in order to analyze the copper(ii) ions?
600-640 nm
640-700 nm
450-560 nm
450-480 nm

Explanation:

Copper(II) ions appear blue because they reflect blue light and absorb the complementary color. On the given color wheel, the complementary color to blue (450-480 nm) is orange-red, which corresponds to the 600-640 nm wavelength range. Spectrophotometers measure absorbed light, so we use the complementary wavelength of the observed color.

Answer:

A. 600-640 nm