Spectroscopy and Electromagnetic Spectrum
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AP Chemistry › Spectroscopy and Electromagnetic Spectrum
What photon wavelength can promote a transition from the n = 1 (ground state) to the n = 3 (excited state)?
204 nm
306 nm
102 nm
408 nm
1 m
Explanation
What is the energy of a photon that has a wavelength of 540 nm?
None of the above
Explanation
A student has a Blue #1 dye with a molar absorptivity of 1.30 x 105 M-1 cm-1 at 631 nm. If the student runs this sample through a spectrophotometer and finds it has an absorption of 0.500 what is the dye’s molarity? Assume a path length of 1.0 cm.
Explanation
A 3.0 eV light is shined on Gold ( Փ = 5.1 eV), silver (Փ =4.26 eV), Cesium (Փ = 2.1 eV), and Platinum (Փ = 6.35). If Փ is the work function of the metal, what metal would have electrons ejected?
Au
Ag
Cs
Pt
Au, Ag, and Pt
Explanation
The work function is the energy required to remove an electron from a metal. Only Cs metal has a work function less than the energy of the light.
What transition would emit the longest wavelength of light?
n = 4 to n = 1
n = 3 to n = 1
n = 2 to n = 1
n = 4 to n = 3
Not enough information given
Explanation
Wavelength is inversely proportional to energy. Since the transition from n=4 to n=3 is the lowest energy transition, it would have the longest wavelength.