Chem 111 Final PSU UPDATED ACTUAL QUESTIONS AND CORRECT ANSWERS
Exp. 2 - Spectroscopy
Define Spectroscopy Study of the interactions of electromagnetic radiation with matter
Explain the difference between a line and continuous Continuous spectrum contains all frequencies within a region of the
spectrum, and give an example of each source of light electromagnetic spectrum.
eg. sun
Line spectrum contains only certain frequencies.
eg. neon lamp
What kind of energy transitions were observed in this Balmer Series (380 - 750 nm)
experiment?
Describe what is meant by the term "white light," and Small band of radiation that can be seen by the human eye (400 - 800 nm).
know the wavelength range that white light covers. List Includes the colors red, orange, yellow, green, blue, and violet.
the colors of the spectrum from the highest to the lowest
frequency.
Explain the purpose of the "discharge tube" in this The discharge tube contains H gas. The voltage source runs a current (electrons)
experiment. through the discharge tube, exciting the electrons in the gas. H's emission
spectrum can then be seen but it is only excited to certain levels so you can only
see certain frequencies.
Explain the effect on the spectrum of changing (a) the slit (a) changes the width of the spectral lines viewed through spectroscope.
width and (b) the distance from the source of light. (b) changes the intensity of the light.
, Outline in a few sentences how you calibrated your Viewed a light source and recorded line spectra that was found per line units. For
spectroscope. this experiment we used a fluorescent light. Once the lines were recorded we
plotted a graph of wavelength vs. distance. We used a best fit line to find our
slope and calibration equation.
If you are given the wavelengths of light observed by a (a) c = (lambda)*v
particular student for the hydrogen emission spectrum (b) E = hv
you should be able to (a) determine the frequencies and (c) E = hv/(lambda)
the energies associated with these wavelengths, (b) be E = Rh[(1/h)i^2 - (i/h)f^2]
able to use the Bohr equation to calculate the wavelenths
expected for the Balmer series of the hydrogen atom, (c)
be able to quantitatively compare results and Bohr's
Exp. 3 - Small-Scale Techniques
Explain the complementary nature of Depending on the wavelength, colors are absorbed or observed. Low
absorbed/observed colors. wavelengths absorb violet and high wavelengths absorbed. Each wavelength
observed color is opposite its absorbed.
What is the fundamental reason why a substance absorbs It depends on the number of interactions between photons and the absorbing
visible light? molecules.
Describe the technique of calorimetry. Uses solutions of known concentrations of a light absorbing substance, in order to
compare the light absorption of an unknown solution. Concentration can be
obtained when a color match is found.
What process removes the energy from excited food dye Solvent molecules bumping billions of times per second against the excited food
molecules in aqueous solution? molecules.
Be able to use the dilution equation given in this CiVi = CfVf
experiment to solve dilution problems.
Be able to describe the observations of OTO with tap When tap water was reacted, the solution turned yellow due to high chlorine ion
water and water passed through the Brita filter. Explain. concentration. The Brita water turned a slightly lighter shade of yellow due to the
Cl ions being removed because it stuck to the activated carbons which have tiny
pores so there is a high surface area to react.
Be able to calculate a standard deviation by hand for a sum([(xi-x)^2/N-1]^1/2)
given data set.
where x = mean (x bar)
Exp. 4 - Use and Abuse of Aluminum
Give two reasons why aluminum is expensive to produce, Depletion of high grade deposits
and two uses for the alum compound that you Hall-Heroult process
synthesized. Deodorant, medicine
Explain the difference between the corrosion of iron and Iron rusts quickly, aluminums outer surface reacts with oxygen, forming a
the corrosion of aluminum. protective film.
Exp. 2 - Spectroscopy
Define Spectroscopy Study of the interactions of electromagnetic radiation with matter
Explain the difference between a line and continuous Continuous spectrum contains all frequencies within a region of the
spectrum, and give an example of each source of light electromagnetic spectrum.
eg. sun
Line spectrum contains only certain frequencies.
eg. neon lamp
What kind of energy transitions were observed in this Balmer Series (380 - 750 nm)
experiment?
Describe what is meant by the term "white light," and Small band of radiation that can be seen by the human eye (400 - 800 nm).
know the wavelength range that white light covers. List Includes the colors red, orange, yellow, green, blue, and violet.
the colors of the spectrum from the highest to the lowest
frequency.
Explain the purpose of the "discharge tube" in this The discharge tube contains H gas. The voltage source runs a current (electrons)
experiment. through the discharge tube, exciting the electrons in the gas. H's emission
spectrum can then be seen but it is only excited to certain levels so you can only
see certain frequencies.
Explain the effect on the spectrum of changing (a) the slit (a) changes the width of the spectral lines viewed through spectroscope.
width and (b) the distance from the source of light. (b) changes the intensity of the light.
, Outline in a few sentences how you calibrated your Viewed a light source and recorded line spectra that was found per line units. For
spectroscope. this experiment we used a fluorescent light. Once the lines were recorded we
plotted a graph of wavelength vs. distance. We used a best fit line to find our
slope and calibration equation.
If you are given the wavelengths of light observed by a (a) c = (lambda)*v
particular student for the hydrogen emission spectrum (b) E = hv
you should be able to (a) determine the frequencies and (c) E = hv/(lambda)
the energies associated with these wavelengths, (b) be E = Rh[(1/h)i^2 - (i/h)f^2]
able to use the Bohr equation to calculate the wavelenths
expected for the Balmer series of the hydrogen atom, (c)
be able to quantitatively compare results and Bohr's
Exp. 3 - Small-Scale Techniques
Explain the complementary nature of Depending on the wavelength, colors are absorbed or observed. Low
absorbed/observed colors. wavelengths absorb violet and high wavelengths absorbed. Each wavelength
observed color is opposite its absorbed.
What is the fundamental reason why a substance absorbs It depends on the number of interactions between photons and the absorbing
visible light? molecules.
Describe the technique of calorimetry. Uses solutions of known concentrations of a light absorbing substance, in order to
compare the light absorption of an unknown solution. Concentration can be
obtained when a color match is found.
What process removes the energy from excited food dye Solvent molecules bumping billions of times per second against the excited food
molecules in aqueous solution? molecules.
Be able to use the dilution equation given in this CiVi = CfVf
experiment to solve dilution problems.
Be able to describe the observations of OTO with tap When tap water was reacted, the solution turned yellow due to high chlorine ion
water and water passed through the Brita filter. Explain. concentration. The Brita water turned a slightly lighter shade of yellow due to the
Cl ions being removed because it stuck to the activated carbons which have tiny
pores so there is a high surface area to react.
Be able to calculate a standard deviation by hand for a sum([(xi-x)^2/N-1]^1/2)
given data set.
where x = mean (x bar)
Exp. 4 - Use and Abuse of Aluminum
Give two reasons why aluminum is expensive to produce, Depletion of high grade deposits
and two uses for the alum compound that you Hall-Heroult process
synthesized. Deodorant, medicine
Explain the difference between the corrosion of iron and Iron rusts quickly, aluminums outer surface reacts with oxygen, forming a
the corrosion of aluminum. protective film.
