Remember: This sheet will not be graded. Put all work on your answer sheet!!!! Put your version, name and ID on
your answer sheet or you will lose points!
40050: Version A: Instructions
Midterm is worth 25 points, not including extra credit, which gives you up to 8 extra points.
RIGHT NOW- fill in your ID number, the bubbles and your version letter on the answer sheet, do this now so you don’t
You’ll lose 5 points if you don’t do this on the front page of
the answer sheet.
forget.
There are multiple versions of the exam. The short answers are mostly just rearranged or words such as “increased” are
replaced with “decrease”. The long answers have similar switches as well as changing the numbers around. This makes it
so that if you copy, you are most likely copying the wrong answer, this makes cheating even more pointless than
normal, please don’t do it.
If you think someone nearby may be copying, or something is simply disturbing you, please let me know and we can
adjust people’s seats appropriately. Tell me as early as possible.
Be sure to sign the sign in sheet. This is my record that you attended the class. If you are not sitting in your assigned
seat for a reason approved by me, you’ll need to make sure to write the seat where you are actually sitting next to your
name. I know this is mildly distracting during a stressful exam but it makes sure that if your exam is lost, which I have
heard horror stories of from other professors, that you have proof that you attended class. It is for your benefit!!!!
You will also need to show your ID to the TA when you turn in your exam.
Only the answer sheet will be graded. You may (and should) keep the exam sheet. Go home, retake it, see
how you did . If you write any work on scrap paper, the question sheet or anywhere other than the space given, it will
not be graded and you will not get any credit for it. Do not write on the back of the sheets, do not write anything you
want graded anywhere other than the space given. I’d suggest writing in pencil or doing scratch work elsewhere and
then copying over.
I think it’s a fairly long exam. Pace yourself, pay attention to point distribution and do your best to complete it all.
Exams will be sent through eee dropbox. They will be graded the same day as you take it but the scanning department
(who have nothing to do with me or the TAs) take a week to get them back to you. It will be returned to you via the
dropbox (note: not the gradebook, the dropbox) the moment that I get the email allowing me to do so.
Finally, relax. At that point there is nothing that being stressed will do for you. So take a deep breath, pick up your
writing utensil and show me how amazing you are at chemistry!
Remember this sheet will not be graded, put all answers on your answer sheet. Put your version, name and ID on your
answer sheet or you will lose points
Remember: This sheet will not be graded. Put all work on your answer sheet!!!! Put your version, name and ID on
your answer sheet or you will lose points!
Remember this sheet will not be graded, put all answers on your answer sheet. Put your version, name and ID on your
answer sheet or you will lose points
Remember: This sheet will not be graded. Put all work on your answer sheet!!!! Put your version, name and ID on
your answer sheet or you will lose points!
STP=O oC and 1 atm
Remember this sheet will not be graded, put all answers on your answer sheet. Put your version, name and ID on your
answer sheet or you will lose points
Remember: This sheet will not be graded. Put all work on your answer sheet!!!! Put your version, name and ID on
your answer sheet or you will lose points!
Remember this sheet will not be graded, put all answers on your answer sheet. Put your version, name and ID on your
answer sheet or you will lose points
Remember: This sheet will not be graded. Put all work on your answer sheet!!!! Put your version, name and ID on
your answer sheet or you will lose points!
Long Answer: Problem 1 (adapted from sapling)
Version A) Violet laser light occurs at a wavelength of 0.350 micrometers. A violet laser produces a pulse with an energy
of 0.250 J. What is the energy of the photons? How many photons are present in each pulse? If the pulse takes 0.500
seconds, how many photons per second are released?
5.68x10-19 J
4.40x1017
8.81x1017
Long Answer: Problem 2 (adapted from slides)
Version A) The work function for calcium is 7.53x10-19 J. What is the minimum frequency of light for the photoelectric
effect for calcium. Then calculate the kinetic energy of the ejected electron if the light of frequency 1.60x1015 s-1 is used
for irradiating the metal.
1.14x1015Hz
3.07x10-19 J
Long Answer: Problem 3 (adapted from sapling)
Version A) A line in the Paschen series of hydrogen has a wavelength of 1090 nm. From what state did the electron
originate? (Hint: the Paschen series all have a final energy level of 3).
6
Long Answer: Problem 4
Explain the difference between destructive and constructive interference. How does this relate to the young’s double slit
experiment? (Adapted from slides, and previous exams)
Destructive= cancelling out/subtracting/lowering Constructive= increasing/adding
Gives interference patterns: bright=constructive dim=destructive
Long Answer: Problem 5 (adapted from slides)
Describe how scientists can use light from other stars to determine their temperatures.
Using Weins law the lambda max can be used to find the temperature (make sure you said something about lambda
MAX, or wavelength of maximum intensity, or some other way implied that there is more than one wavelength coming
off)
Short Answer
Remember this sheet will not be graded, put all answers on your answer sheet. Put your version, name and ID on your
answer sheet or you will lose points
Remember: This sheet will not be graded. Put all work on your answer sheet!!!! Put your version, name and ID on
your answer sheet or you will lose points!
Write the formula for each: (bookwork/slides)
1) Calcium Chlorate
Ca(ClO3)2
2) Sodium Chloride
NaCl
Write the name for each: (bookwork/slides)
3) PCl3
Phosphorous trichloride
4) H2SO3
Sulfurous acid
5) A team of scientists recently developed a series of
nanowires that can act as miniature lasers. One
nanowire was found to emit light of frequency
8.73x1014Hz. What was the wavelength of the light?
(worksheet)
8) The graph labelled A represents: wavefunction or
position (although position isn’t strictly correct, we
allowed it) or psi
9) The graph labeled B represents: probability density or
psi squared
10) The number of nodes equals: 1
----------------------------------------------------------------------11) What is the uncertainty in the position of an
electron moving at 4.00x106 m/s with an uncertainty in
velocity of 1.00x104. (sapling)
5.79x10-9
3.43x10 m
12) If you decreased the uncertainty in the velocity,
what would happen to the uncertainty in the position?
(adapted from slides)
6) For the nanowire in the previous problem, what is
the energy of the emitted radiation? (adapted from
slides and bookwork)
increased
-7
-19
5.78x10 J
7) Mulder weighs 180 pounds, Scully weighs 140, who
has the longer wavelength? (adapted from slides)
13) Given the following reaction, calculate the
maximum mass of copper (II) hydroxide that can be
formed when 2.00 g of sodium hydroxide is added to
80.0 mL of 0.500 M Cu(NO3)2 (bookwork).
Cu(NO3)2 +2NaOH  2Na(NO3)+ Cu(OH)2
2.44g
scully
Use the picture below of a particle in a box model to
answer the following questions. (adapted from slides)
14) How many orbitals in a single atom may have the
quantum numbers: n=5 or 4, l=3, ms=+1/2
14
15) How many electrons in a single atom may have the
quantum numbers: n=5 or 4, l=3, ms=+1/2
14
16) (adapted from slides) In Young’s double slit
experiment the bright areas of light are due to
constructive interference. (two words)
Remember this sheet will not be graded, put all answers on your answer sheet. Put your version, name and ID on your
answer sheet or you will lose points