4. Analytical Techniques

Spectroscopic Analysis — Quiz

Test your understanding of spectroscopic analysis with 5 practice questions.

Practice Questions

Question 1

In a UV–Vis experiment, a solution with absorbance $A=0.680$ at its absorption maximum $\lambda_{\max}$ was measured in a $1.00\ \mathrm{cm}$ cuvette with known concentration $c=5.00\times10^{-5}\ \mathrm{M}$. What is the molar absorptivity $\varepsilon$ in $\mathrm{M^{-1}\,cm^{-1}}$?

Question 2

In a DEPT-135 $^{13}\mathrm{C}$ NMR experiment, which statement correctly describes the appearance of signals for different carbon types?

Question 3

In a $400\ \mathrm{MHz}$ $^1\mathrm{H}$ NMR spectrum, two doublet peaks are separated by $0.012\ \mathrm{ppm}$. What is the coupling constant $J$ in hertz?

Question 4

A mass spectrum shows a molecular ion peak at $m/z=78$ and an M+2 peak with approximately one-third the intensity of the M peak. Which element is indicated?

Question 5

Which region of an IR spectrum is known as the fingerprint region and is most useful for distinguishing positional isomers?