This document contains 27 multiple choice and short answer questions related to chemistry concepts such as properties of matter, chemical equations, periodic trends, and reactions. It provides guidance on using online resources like Wolfram Alpha, Khan Academy, periodic tables, and unit converters to find answers. However, it notes that for some questions, understanding the underlying chemistry concepts is still necessary to select the right approach and apply significant figures correctly.

1. Scott Morris, Ph.D.
St. Gregory College Preparatory School

2. Properties, Units, Measurements
1) Why are intensive properties more important than
extensive properties? (2 pts)
[From notes or answers.com]
2) Give an example of an intensive property. (2 pts)
[From notes or answers.com]
3) Give two lines of evidence (observations) that would
suggest chemical change. (2 pts)
[From notes or answers.com]

3. 4) A student is measuring the density of an
irregular object. The mass of the object is 6.97
g and when placed in a graduated cylinder with
water, the water level raises 3.5 mL. Calculate
the density of the object. Show work or indicate
specific solution method (reproduce text
entered in command line of Wolfram). (3 pts)
[Most students use Wolfram and make it a math
problem, or a density problem. They have to
know/remember to apply significant figure
rules to their answer--Wolfram has no way of
know that the numbers are measurements, so it
returns and outrageous precision]

4. 5) How many nanometers are there in a kilometer? Show
work or indicate specific solution method (reproduce text
entered in command line of Wolfram). (3 pts)
[Again, Wolfram is the popular solution, although
there are various "unit converters" out there as well. I
have an app on my Droid]

5. 6) Answer the following questions about the isotope. (3
pts)
108Ag1+ a) number of protons _____________
b) number of neutrons ____________
c) number of electrons ____________
[ptable.com provides data, but does not answer the
question directly. The student must understand isotope
notation]

6. 7) Calculate the frequency of radiation with a wavelength
of 115 nm. Show work or indicate specific solution
method (reproduce text entered in command line of
Wolfram). (3 pts)
[Wolfram is the general solution method, although
failure to understand the relationships between photon
wavelength, frequency, and energy often leads to incorrect
answers. Here a case where one needs to understand how
Wolfram structures this particular "knowledge" to get the
correct answer]

7. 8) Calculate the energy of a photon with a wavelength of
525 nm. Show work or indicate specific solution method
(reproduce text entered in command line of Wolfram). (3
pts)
[Same as above--a slightly different calculation. In
all cases, the rules governing the significant figures of the
answer apply, and students must understand them apart
from the numerical answer]

8. 9) Classify the following bonds as ionic (I) or covalent
(C) and explain your rationale (1 pt each).
H and Cl ___________ Cl and Cl _________ N and O
_________ Na and Br _____
[Most easily answered from notes or previous worked
examples. These require consultation of a table of
electronegativities -- most students use ptable.com]

9. 10) How many lone pairs are there on the oxygen atom of
a water molecule? Explain how you know. (2 pts)
[Google water molecule, look for images…. The student
needs a basic understanding of the octet rule to learn
which of the (countless) images is the one that will help
answer the question. Also the student must understand the
important concept of bonding pairs (of electrons) and lone
pairs in molecules]

10. 11) Name the following polyatomic ions. (1 pt each)
NO21- ________________ CrO42- ____________________
SO42- ____________________
[enter formula into Wolfram or Wikipedia and correct name will be
displayed. Student needs to understand the importance of the
charge, other wise they can easily get the wrong name. Here is one
of the many topics (naming polyatomic ions) where students in the
past had to just memorize a couple dozen of these. I do not see the
point of that "exercise" any more. If the student works with the
common compounds in labs, they will recognize the common ions
by the end of the year. There is in my view, no lasting benefit to
memorizing these]

11. 12) Write the word equation (including phase
information) for the following. (2 pts)
Zn(s) + CuSO4 (aq)  ZnSO4(aq) + Cu(s)
[Enter element symbols/compounds into
Wolfram/Wikipedia and get back the names. The student
must know what the subscripted symbols represent (and
putting them in the formulas causes incorrect answers
from Wolfram]

12. Physical Properties of elements and compounds (1 pt each)
13) Melting point of molybdenum ______________________
14) Boiling point of gold _________________________
15) Phase (solid, liquid, gas) of sulfur at 300 K ____________________
16) Density of osmium _____________________
17) Melting point of potassium hydroxide ______________________
Periodic Properties (1 pt each)
18) Electronegativity of carbon _______________________
19) Valence of magnesium _________________________
20) Ionization energy of cesium ___________________
21) What is the electron configuration of molybdenum? ________________________
22) What is the principle quantum number of the valence electrons in an atom of gold? _____________
23) How many unpaired electrons are there in an atom of ruthenium? ____________
[ptable.com is an amazing resource. It not only lists the basic information about the elements, it has an
extensive interactive electron orbital tab, as well as let's the user change the temperature. This is a game-
changer in terms of the sophistication of questions that can be asked, and I have yet to tap its full
potential]

13. 24) Assign oxidation numbers to each element in the following
compounds: (2 pts each)
HClO ___________________________
CrO42- ____________________________
[Students have to get this "old school." I/they have not found any
easy solution using internet resources. They can find the rules for
assigning the numbers, but they have proven to be problematical
through the years. If they have saved (and can find) some examples
that we worked in class, the problem is much easier.]

14. 25) The table below contains data about the molar mass, flame temperature, and
dominant wavelength (flame color) for a sample of organic compounds.
molar mass flame temperature dominant wavelength
(g/mol) (K) (nm)
180 1510 500
60 1875 420
45 1900 425
98 1715 500
113 1755 525
160 1650 580
35 1950 415
225 1450 625
155 1615 575
82 1810 440
75 1850 450
57 1920 420
94 1425 575
55 1900 415
a). Describe the relationship, if any, between molar mass and flame temperature.
Prepare an appropriately labeled scatterplot. Are there any unusual points that don't fit?
If so, describe them. (4 pts)
b) Describe the relationship, if any, between flame temperature and dominant
wavelength. Prepare an appropriately labeled scatterplot. Are there any unusual points
that don't fit? If so, describe them. (4 pts)
c) Paste both scatterplots into a new document, label it question 25, and email
it to me.
[Here is where I think the future is going--real time data
analysis, presentation and submission. They send me (or share via
Googledocs) their output. I plan on doing more with this in the future]

15. 26) Calculate the theoretical yield of carbon dioxide (in mols)
when 125 g of sodium hydrogen carbonate decomposes
according to the following balanced chemical equation. Show
work or explain your solution method. (4 pts)
2NaHCO3(s)  CO2(g) + H2O(g) + Na2CO3(s)
[Very adroit Wolfram uses can get a lot of assistance on a
problem like this one, but to date, I have not seen anyone get
the "answer." Again, a well-organized student should be able
to find a couple nicely annotated similar problems in their
notes (or my posted notes, if they know where to look) and get
the answer.]

16. 27) Write chemical equations that describe the following
reactions. If no reaction, write NR. (3 pts each)
A. Molten calcium is put into a container of iodine gas.
B. 1-Propanol is burned in air.
C. Solid calcium sulfite is strongly heated in a vacuum.
D. A piece of zinc metal is put into distilled water.
E. A piece of iron is put into a solution of silver nitrate.
F. Chlorine gas is bubbled through a solution of sodium iodide.
G. A piece of nickel is put into a solution of hydrochloric acid
[These are the most challenging questions on the exam. There is no single
source of information that will return the correct answers. As above, a well-
organized student should be able to quickly determine the category of the
reaction, and then consult similar reaction notes. Some students took pictures
(with their phones, of course) of all their worksheets and tried to get at it that
way. They were not generally successful because the worksheets contained a
mix of problem types. My recommendation was to group all the examples we
did by reaction type, and make notes on how the different permutations were
related]

17. I pledge that I have used my laptop resources appropriately
during this exam. I have not directly given nor received
information from another person during this exam.
Signed __________________________________
[Although I may be naïve, I think the pledge is especially
important to the new "sensibility"-- Archived sources (all the
information on the internet) or AI resources (Wolfram) are
there to be used!]