Spectroscopy
UV-Vis spectroscopy of organic compounds is usually concerned with which electronic transition(s)?

n → σ*
σ → σ*
none of these
n → π* and π → π*

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Spectroscopy
Why must the voltage supplied to a tungsten lamp be very stable?

Because if it wasn't, the lamp would bum out
All of these
Because the lamp will only function at a specific voltage
Because amount of energy the lamp emits is proportional to the fourth power of the operating voltage

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Spectroscopy
Why are rotational transitions of little use to a spectroscopist?

Because rotational transitions are extremely rare
All of these
Because, in liquids and solids, spectral lines corresponding to rotational transitions are broadened as the result of molecular collisions and other interactions
Because the energy required to induce a rotational transition is so small that it cannot be measured

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Spectroscopy
Why is it generally preferable to use absorbance as a measure of absorption rather than % transmittance?

Because %T cannot be measured as accurately as absorbance
Because %T is dependant on the power of the incident radiation
None of these
Because absorbance is proportional to the concentration of the analyte, whereas %T is not

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