CHEM 111 Final Exam UPDATED ACTUAL QUESTIONS AND CORRECT ANSWERS
Know your significant figure rules ALL zeroes between non-zero numbers are ALWAYS significant.
ALL zeroes which are SIMULTANEOUSLY to the right of the decimal point
AND at the end of the number are ALWAYS significant.
ALL zeroes which are to the left of a written decimal point and are in a
number >= 10 are ALWAYS significant.
define calorimetry the act of measuring heat required or evolved during a chemical process
know how to calculate the amount of energy E= energy [J]
produced using E= m∙c∙deltaT m= mass [kg]
c= specific heat capacity
delta t= change in temp
Define what is meant by a small calorie "c" and food calorie= amount energy needed to raise temperature of one gram of water
calorie "C" by one degree C
1 food cal= 1000 small cal= 1 Kcal
When walking, an average person burns 0.453 Food ((0.453 Food Calories)/mile-pounds)x150 lbs x 1 mile= 67.95 Cal
Calories/ mile-pounds. How many food calories does 67.95 Cal x (1peanut/5.6 Food Calories)= 13
a 150-pound person burn after walking a mile? If a
peanut realizes 5.7 Food Calories/g and an average
peanut weighs about 1 gram, then how many
peanuts will you have to eat to walk a mile?
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 a source of each electromagnetic spectrum. produced by the sun and heated solids e.g.- sun
type
Line spectrum- contains only certain frequencies and produced by excited
atoms in the gas phase. e.g.- neon lamp
What kind of energy transitions were observed in Balmer Series (380-750 nm)
experiment 2: spectroscopy?
Describe the term "white-light", and know the small band of radiation that can be seen by the human eye.
wavelength range (in nm). List the colors of the 400-800 nm
spectrum from highest to the lowest frequency violet>blue>green>yellow>orange>red
(high to low)
Purpose of typical "discharge tube" used to see visible radiation. it results in the emission of light that can be
analyzed by a spectroscope
The glass tube is attached to the high voltage system. When it is turned on,
fast moving e- shoot through the gas (at low pressure) from cathode to
anode. Energy is transferred from the e- to the gas atoms and the e- are
excited to higher energy levels. The return on the excited atoms results in
the emission of light.
Explain the effect on the spectrum of changing a) the a) changes width of the spectral lines viewed through spectroscope
slit width b) the distance from the source of light to b) changes the intensity of the light
the spectrum
Outline in a few sentences how you calibrated your viewed a known light source and recorded line spectra that was found per
spectroscope line units. we then plotted a graph of wavelength vs. distance. We used a
best fit line to find our slope and calibration equation.
Given wavelengths of light determine: a) frequencies c=λv
and energies b) use Bohr equation to calculate the
wavelengths expected for the Balmer series of the E=hv
hydrogen atom c) be able to quantitatively compare
the results of a) and b)- i.e. know how to calulate the E=hv/ c
% difference between a student's results and Bohr's.
Constants given E=Rh(1/ni² - 1/nf²)
in balmer series nf=2
Explain the complementary nature of Low wavelengths absorb violet and high wavelengths absorb red. Each
absorbed/observed colors wavelength observed color is opposite its absorbed.
whatever color is absorbed its complements is observed
Describe the technique of colorimetry 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.
Know your significant figure rules ALL zeroes between non-zero numbers are ALWAYS significant.
ALL zeroes which are SIMULTANEOUSLY to the right of the decimal point
AND at the end of the number are ALWAYS significant.
ALL zeroes which are to the left of a written decimal point and are in a
number >= 10 are ALWAYS significant.
define calorimetry the act of measuring heat required or evolved during a chemical process
know how to calculate the amount of energy E= energy [J]
produced using E= m∙c∙deltaT m= mass [kg]
c= specific heat capacity
delta t= change in temp
Define what is meant by a small calorie "c" and food calorie= amount energy needed to raise temperature of one gram of water
calorie "C" by one degree C
1 food cal= 1000 small cal= 1 Kcal
When walking, an average person burns 0.453 Food ((0.453 Food Calories)/mile-pounds)x150 lbs x 1 mile= 67.95 Cal
Calories/ mile-pounds. How many food calories does 67.95 Cal x (1peanut/5.6 Food Calories)= 13
a 150-pound person burn after walking a mile? If a
peanut realizes 5.7 Food Calories/g and an average
peanut weighs about 1 gram, then how many
peanuts will you have to eat to walk a mile?
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 a source of each electromagnetic spectrum. produced by the sun and heated solids e.g.- sun
type
Line spectrum- contains only certain frequencies and produced by excited
atoms in the gas phase. e.g.- neon lamp
What kind of energy transitions were observed in Balmer Series (380-750 nm)
experiment 2: spectroscopy?
Describe the term "white-light", and know the small band of radiation that can be seen by the human eye.
wavelength range (in nm). List the colors of the 400-800 nm
spectrum from highest to the lowest frequency violet>blue>green>yellow>orange>red
(high to low)
Purpose of typical "discharge tube" used to see visible radiation. it results in the emission of light that can be
analyzed by a spectroscope
The glass tube is attached to the high voltage system. When it is turned on,
fast moving e- shoot through the gas (at low pressure) from cathode to
anode. Energy is transferred from the e- to the gas atoms and the e- are
excited to higher energy levels. The return on the excited atoms results in
the emission of light.
Explain the effect on the spectrum of changing a) the a) changes width of the spectral lines viewed through spectroscope
slit width b) the distance from the source of light to b) changes the intensity of the light
the spectrum
Outline in a few sentences how you calibrated your viewed a known light source and recorded line spectra that was found per
spectroscope line units. we then plotted a graph of wavelength vs. distance. We used a
best fit line to find our slope and calibration equation.
Given wavelengths of light determine: a) frequencies c=λv
and energies b) use Bohr equation to calculate the
wavelengths expected for the Balmer series of the E=hv
hydrogen atom c) be able to quantitatively compare
the results of a) and b)- i.e. know how to calulate the E=hv/ c
% difference between a student's results and Bohr's.
Constants given E=Rh(1/ni² - 1/nf²)
in balmer series nf=2
Explain the complementary nature of Low wavelengths absorb violet and high wavelengths absorb red. Each
absorbed/observed colors wavelength observed color is opposite its absorbed.
whatever color is absorbed its complements is observed
Describe the technique of colorimetry 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.
