Describe the basic design difference between a spectrometer for absorption measurements and one for emission studies.

Why does a deuterium lamp produce a continuum rather than a line spectrum in the ultraviolet range?

A portable photometer with a linear response to radiation registered a photocurrent of $75.9 \mu \mathrm{A}$ with a blank solution in the light path. Replacement of the blank with an absorbing solution yielded a response of $23.5 \mu \mathrm{A}$. Calculate (a) the percent transmittance of the sample solution. *(b) the absorbance of the sample solution. (c) the transmittance to be expected for a solution in which the concentration of the absorber is one third that of the original sample solution. *(d) the transmittance to be expected for a solution that has twice the concentration of the sample solution.

A portable photometer with a linear response to radiation registered $83.2 \mu \mathrm{A}$ with a blank solutior in the light path. Replacement of the blank with ar absorbing solution yielded a response of $45.1 \mu \mathrm{A}$ Calculate

(a) the percent transmittance of the sample solution.

"(b) the absorbance of the sample solution.

(c) the transmittance to be expected for a solution in which the concentration of the absorber is one-third that of the original sample solution.

*(d) the transmittance to be expected for a solution that has twice the concentration of the sample solution.

A photometer with a linear response to radiation gave a reading of $625 \mathrm{mV}$ with a blank in the light path and $149 \mathrm{mV}$ when the blank was replaced by an absorbing solution. Calculate *(a) the percent transmittance and absorbance of the absorbing solution. (b) the expected percent transmittance if the concentration of absorber is one half that of the original solution. *(c) the percent transmittance to be expected if the light path through the original solution is doubled.

A photometer with a linear response to radiation gave a reading of $595 \mathrm{mV}$ with a blank in the light path and $139 \mathrm{mV}$ when the blank was replaced by an absorbing solution. Calculate

*(a) the percent transmittance and absorbance of the absorbing solution.

(b) the expected transmittance if the concentration of absorber is one-half that of the original solution.

*(c) the transmittance to be expected if the light path through the original solution is doubled.

What are the major advantages of Fourier transform IR instruments over dispersive IR instruments?

What experimental variables must be controlled to assure reproducible absorbance data?

What is the purpose of (a) the $0 \%$ adjustment and (b) the $100 \%$ adjustment of a spectrophotometer?

What minimum requirement is needed to obtain reproducible results with a single-beam spectrophotometer?

Describe the differences between the following pairs of terms and list any particular advantages possessed by one over the other: *(a) solid-state photodiodes and phototubes as detectors for electromagnetic radiation. (b) phototubes and photomultiplier tubes. *(c) filters and monochromators as wavelength selectors. (d) conventional and diode-array spectrophotometers.

Describe the differences between the following and list any particular advantages possessed by one over the other:

*(a) filters and monochromators as wavelength selectors

(b) solid-state photodiodes and phototubes as detectors of electromagnetic radiation

*(c) phototubes and photomultiplier tubes

(d) conventional and diode-array spectrophotometers

What are the two subfields into which economics is divided? Explain what each subfield studies.

Describe why the claims of these studies might be suspect.

In High Point County there are 672 raccoons.