6. Techniques and Applications

Spectroscopy — Quiz

Test your understanding of spectroscopy with 5 practice questions.

Practice Questions

Question 1

In UV–vis spectroscopy, if a sample transmits 20% of incident light at a given wavelength, what is its absorbance A?

Question 2

A chromophore shows an absorption maximum at 400 nm in solvent A and at 420 nm in solvent B. This shift to a longer wavelength is called:

Question 3

A fluorophore has quantum yield $\phi=0.30$ and fluorescence lifetime $\tau=4.0\,\mathrm{ns}$. What is its non‐radiative decay rate constant $k_{nr}$?

Question 4

In a FRET experiment, the energy transfer efficiency is $E=0.60$ and the Förster radius is $R_0=5.0\,\mathrm{nm}$. What is the donor–acceptor distance $r$?

Question 5

A protein of 100 residues (mean residue weight 110 Da) at concentration 0.2 mg/mL yields an observed CD ellipticity 200 mdeg at 222 nm in a 0.1 cm cell. Calculate the mean residue ellipticity [θ] (deg·cm^2·dmol^−1) using $$[\theta]={\theta_{obs}\times\mathrm{MRW}\over10\,c\,l}\,. $$