Prep Sheets last modified on January 9, 2008 by Gary Mines
CHM 121 Prep Sheet – Exp 2. Paper Chromatography (Slowinski, 8th Ed.)
(for a class of 24 students working in pairs)
Students will use the 600 mL beakers in their drawers as chambers for the paper
chromatographic separation and identification of metal ions.
(1) 12 pieces of Whatman # 1 cut to 11 cm x 19 cm (ordered as roll of paper with 19 cm width)
(2) Additional Whatman #1, circular, for practice spotting (students can use the paper in their
drawers—do they have paper at RHC in drawers?)
(3) 12 rulers, scotch tape, and grease pencils (scissors as well, if students will be cutting their
own paper from roll)
(4) 2 vials capillary tubes for spotting **Open on both ends; not the ones used for mp determinations.**
(5) 300 mL of Eluting Solution1 (Note: have at least 2 x 150 mL bottles of this solution)
(6) 5 small dropper bottles, one for each of the following solutions. (Each section will use only
5-10 mL of each solution)
 0.1 M AgNO3
 0.1 M Co(NO3)2
 0.1 M Cu(NO3)2
 0.1 M Fe(NO3)3
 0.1 M Hg(NO3)2
(7) Staining solution2 in 4 spray bottles producing a fine spray
(8) Unknowns. Each student unknown is prepared in a small test tube (or alternatively in a small
vial) and should contain 2-3 drops each (or any equal amounts) of the solutions listed in # (6)
above in the combinations listed below.
 AgNO3 and Cu(NO3)2 and Fe(NO3)3
 Co(NO3)2 and Fe(NO3)3 and Hg(NO3)2
 Cu(NO3)2 and Fe(NO3)3 and Hg(NO3)2
 AgNO3 and Co(NO3)2 and Hg(NO3)2
1
2
Prepared by mixing 500 mL 6 M HCl with 400 mL of ethanol and 400 mL of n-butanol
Dissolve 8.0 g of K4Fe(CN)6, potassium ferrocyanide, and 3.5 g KI, potassium iodide, in one
liter of deionized water.
Instructor Notes
The Hg2+ appears as a pale yellow-orange ring with a high (~ 1) Rf value. The Ag+ appears as a pale
yellow spot with a very low Rf value (~0.01) and may not be discernable. If students wait until the next
lab period to read their chromatograms (they can leave them in their lab drawers), the Hg2+ and Ag+ show
up more clearly (often as dark bluish spots).
Make sure students do not take more than they need of each solution! (they need << 1 mL each!).
Two "Un." lanes are shown in Figure 2.2, but no mention is made in the write-up of applying the
unknown mixture to two separate lanes. Some students mistakenly (but reasonably!) think that they are
going to use two different unknown mixtures--they should not. (I also find it strange that the term
"known" is used to describe the mixture of all five knowns; each lane with a given cation is a "known" as
well and I think it is good to point this out to students)
I usually use the time during the development of the chromatogram to do worksheets on lecture-related
material rather than to test the spot colors with the stain. Also, if time is running short, one need not wait
a full 75 minutes to get a decent separation.
CHM 121 Prep Sheet – Exp 1. (Parts A, B, and C) Densities of
Liquids and Solids (Slowinski, 8th Ed.)
(for a class of 24 students working in pairs)
(1)
(2)
(3)
(4)
Twelve 25 mL Erlenmeyer flasks with standard taper stoppers for use as pycnometers.
Wash bottles with acetone, about 120-160 mL (total)
Pennies for measuring mass. Many students will opt to use their own coins.
Unknowns – Liquids. Each pair will need at least 30 mL of a liquid unknown. The
liquid unknowns may be of technical quality. Appropriate liquids include the following:



Ethanol, 95%
2-Propanol
Heptane


Cyclohexane
Toluene
(5) Unknowns - Metals. Each pair will need 50 grams of an unknown metal in the form of
shot or small pieces which will fit through the neck of the 25 mL Erlenmeyer flask.
After use the metal needs to be recovered, cleaned by rinsing with acetone, and dried on
a paper towel. Appropriate metals include:
 Aluminum shot
 Lead sheet, 1/16”, cut into 1/2'' x
1/4" pieces
 Bismuth shot
 Lead shot
 Cadmium stick (sawed into slugs and split again)  Tin shot
 Cobalt pellets
 Zinc shot
 Copper shot
For Gary Mines's Section only:
 800 mL 2-propanol (in four 200-mL dropping bottles) as "known"
 Unknowns (15) in Cabinet 21 (2242); only need ~50 mL in each [possibly change from
bottles to large screw-top vials?]. NOTE: (With Dave's consent, use the contents of
these unknown bottles to replenish unknowns in other sections or to use for other
purposes for which very high purity is not critical. Refill unknowns with fresh, pure
solvent each semester unless indicated otherwise.)
Instructor Notes
Be sure that students properly recover, wash, and dry their metal unknowns. Remind students to return
the pycnometers (with stoppers) to the tray (not their drawer!)
The air spigots do work in our lab at DP, but only if the master switch is turned on (located on the wall
just to the left of the stockroom entrance as you face it from the lab). CAUTION: Spigots should
NEVER be turned "fully on" as the pressure will be dangerously high; have students turn the spigot very
carefully so that it is just barely on. N.B. Sometimes condensed water (!) is present in the air lines, so
students should test them out first before using them to dry flasks. Note: Air is always on at RHC.
The manual often states to measure mass "to the nearest milligram". Our balances measure out to the
next decimal place (0.1 mg) and I don't see why they should limit the precision in the measurements
arbitrarily. That being said, in part B, for the more volatile unknown liquids, many students report that
the mass is constantly decreasing (in the last decimal place on the balance) after they've filled the flask
up. Whether this is due to inadequate drying or to poor matching of stoppers with flasks is not certain,
but you may wish to have students round to the nearest milligram in these cases, should problems arise.
CHM 121 Prep Sheet – Exp 6. (Parts A and D) Properties of
Hydrates (Slowinski, 8th Ed.)
(for a class of 24 students working in pairs)
Students will use crucibles, crucible lids, crucible tongs, mats (fiber square), and clay triangles
from their drawers, and test tube racks from the common areas in the lab.
(1) Containers with the following solids. Each container should be marked with the name,
but not the formula, of the solid. Each pair of students will need 0.5 g of each solid (i.e.,
12 g total of each).
 Nickel chloride
NiCl2 . 6H2O
 Potassium chloride
KCl
 Sodium tetraborate (borax) Na2B4O7 . 10H2O
 Sucrose
 Calcium carbonate
CaCO3
 Barium chloride
BaCl2 . 2H2O
(2) 6 M HNO3 (dilute nitric acid) – each bottle provided with a disposable Pasteur pipet.
(PROCEDURE PUT INTO QUESTION BY GAM)
(3) Unknown hydrates. Each pair of students should receive about 1 gram of one of the
following hydrates. (i.e., Assuming 6 samples of each compound for a class of 24, a total
of 6 g of each solid are needed per lab period)
 BaCl2 . 2H2O
 Na2MoO4 . H2O
 K2CO3 . 3/2H2O (omit due to fractional coeff; do not try Na2CrO4 hydrate [toxic!])
 CaSO4 . 2H2O
Instructor Notes
Make sure students do NOT use a plastic test tube rack (they do melt!).
Stress that only a gentle heating should be done in Part A! If students overheat (or heat do dryness), the
tubes are sometimes impossible to clean.
Although the manual says to use "small" test tubes, I have students use the medium-sized tubes since they
are easier to clean (see above).
Students often have trouble making the proper conclusion regarding "water soluble" in Part A. For one
thing, several of the solids in this experiment are slow to dissolve and the amounts they use sometimes
don't dissolve completely in just a few cm3 of water. Also, many students don't attempt to swirl, vortex,
or stir the solution--they expect it to just "disappear" (seemingly right away!) if it is soluble. Lastly, some
students confuse "homogeneous" with "soluble" (esp. with CaCO3; the shaken mixture looks "white like
milk" so some mistakenly conclude that it is soluble). Be on the look-out for these potential problems!
The data table for Part A should really include columns for "Color of solid (before heating)" and "Color
of Solution (if residue redissolves)" because a property of hydrates mentioned in the write-up is that if
their anhydrous salts dissolve, the "solutions have a color similar to the (original) solid hydrate". I tell
students to add those columns to the table (they can squeeze it in!). You must also tell them, however,
that "white" hydrates will not give a "white" solution upon dissolution—it will be "colorless".
CHM 121 Prep Sheet – Exp 4. Determination of a Chemical
Formula (Slowinski, 8th Ed.)
(for a class of 24 students working in pairs)
Each pair of students will need to be provided a Buchner funnel with an adaptor (CAN WE GET
1-HOLE STOPPERS INSTEAD?), a 250 mL filter flask, vacuum tubing that fits flask, and
Whatman #1 filter paper circles of the proper size to fit the Buchner funnel (7 cm diameter?).
Water aspirators are in the lab, and the drying oven will be used in place of a heating lamp.
(1) 2 x 200 mL dropper bottles of dilute hydrochloric acid (6 M HCl)– about 1 mL per pair
(i.e., 15 mL total per class)
(2) 2 x 200 mL Bottles with 95% ethanol – about 10 mL per pair (i.e., 150 mL total per
class)
(3) Aluminum wire. 20 gauge, - 20 cm (~0.25 g) per pair (i.e., 2.4 m (~6 g) per class)
(4) Bottles of CuCl2 . 2H2O1 labeled as CuxCly . zH2O – about 1 g per pair (15 g per class)
(5) 6 M nitric acid (HNO3) for cleaning crucibles (as necessary) (40 mL max per class)
1
This hydrated Copper (II) chloride needs to be quite pure. It should be A.C.S. purity (>99%)
and free pouring.
Instructor Notes
Show students how to pick up the Bunsen burner and move the flame around to gently and
evenly heat; if they leave the burner in one place, it is less likely that they will evenly heat the
solid.
Be prepared to hear many crucible lids fall! Try to warn them to be careful of this and show
them how to place the lid properly ajar with some support. Check to see that the crucible and
clay triangle are a good size match—a large crucible will tip over easily in a small triangle and
occasionally a small crucible can fall through a triangle that has been "widened" to fit a larger
crucible.
Many students want to use a microspatula to mix up the brown crystals to see if the inside has
turned color. I discourage this due to the transfer of material to the spatula.
Be sure to instruct students to clamp the filter flask to a ring stand before use.
Remind them (show them?) that balances will read inaccurately if items are not at room
temperature.
A drying oven can be used to help dry the copper metal (we do not have heating lamps). Tell
students to put their filter paper with copper onto a watch glass for easier handling, and make
sure they initial the watch glass or otherwise remember where they put their sample in the oven
so they don't get mixed up. Alternatively, students can store their copper in their drawers and let
it air dry over the week, if you don't mind them turning in their lab report the following week.
CHM 121 Prep Sheet – Exp 24. (A and B only): The
Standardization of a Basic Solution and the Determination of the
Molar Mass of an Acid (Slowinski, 8th Ed.)
(for a class of 24 students working in pairs)
Each pair of students will need two 50 mL burets (with stopcocks). Please check to make sure
all stopcocks fit snugly into each buret (or pair up stopcocks with burets to ensure snugness of
fit), and also check the Teflon tape-sealed joint for snugness. Leakage has been a problem.
Buret clamps are in a common area in the lab.
Variation in procedure from lab manual: Students will NOT prepare their own NaOH(aq)
solutions. Thus 6 M NaOH(aq) and Florence flasks will not be needed. However, a large
volume of dilute NaOH(aq) will need to be prepared (see below).
(1) 12 sheets of 8.5" x 11" white paper
(2) 24 buret reading cards (white index card with thick black marker line in middle)
(3) ~0.1 M NaOH(aq)—about 2.5 L per section. Can be prepared from 6 M NaOH (44 mL
added to 2.5 L). Solution must be thoroughly mixed, yet not stirred overnight [limit air
exposure due to reaction with CO2]. Best if prepared no more than one day prior to use.
NOTE: do not try to make the NaOH solution have a molarity of 0.1000 M! It is actually better if it is
sometimes 0.105 or 0.0995 M (or more importantly, that it is not “identical” to the molarity of the ~0.1 M HCl.)
(4) ~0.1 M HCl(aq), standardized—about 1.3 L per section. (Try not to make the molarity 0.1000 M!
See note above for NaOH.) *But do standardize to 4 significant figures.*
(5) 2 x 200 mL bottles of 95% ethanol—150 mL per section
(6) 2 x 200 mL dropper bottles of Phenolphthalein Indicator solution—15 mL per section
(For 1 L of solution: dissolve 1 g 2,2-bis(parahydroxyphenyl)-phthalide in 600 mL of
95% ethanol and dilute with water to 1 L)
(7) Unknowns: Change in procedure from lab manual: Each pair will be given a vial with a lot
more solid than they will actually use. Instructors can either choose to tell students to use
~0.6 g of solid per trial (no matter which unknown they have), or they can tell those that
have KHP to use 0.9 g (to get larger titration volume). See table below:
Unknown
mandelic acid
potassium hydrogen phthalate
sodium dihydrogen phosphate
monohydrate (NaH2PO4∙H2O)
sodium hydrogen sulfate
monohydrate (NaHSO4∙H2O)
Molar Mass
(g/mol)
152.1
204.2
mL of 0.1 M NaOH
needed to titrate 0.6 g
39.4 mL
29.4 mL
Amount Needed
Per Pair
1.2 g
1.2-1.8 g
138.0
43.5 mL
1.2 g
138.1
43.4 mL
1.2 g
NOTE: In this new procedure, glycolic acid, (MM = 76.05 g/mol) is being omitted since 0.6 g would lead
to a titration volume of well over 50 mL [~79 mL]. If another acid is desired, perhaps try using sodium
hydrogen tartrate (MM = 190.1 g/mol), which is one of the suggested acids in the lab manual which (for
unknown reasons) has never been used at OCC.
Instructor Notes
See the two noted changes above: 1) Students will be given ~0.1 M NaOH; 2) Tell students to use
~0.6 g of solid for each trial (NOT “half their sample” as is written in the procedure).
CHM 121 Prep Sheet – Exp 30. Determination of Iron by Reaction
with Permanganate: A Redox Titration (Slowinski, 8th Ed.)
(for a class of 24 students working in pairs)
Each pair of students will need a 50 mL buret (with stopcock). Buret clamps are in a common
area in the lab.
(1) Dilute sulfuric acid (6 M H2SO4) – about 400 mL per section
(2) 2 x 200 mL dropper bottles of Phosphoric Acid (85% H3PO4) – about 150 mL per section
(3) Standardized (precise concentration determined by titration against a primary standard)
potassium permanganate1 (0.015 M KMnO4) – about 1.5 liters per section
(4) Unknown iron (iron (II) ammonium sulfate) samples2 – each pair of students should receive
5 grams of an unknown iron sample
(5) 12 buret reading cards (white index card with thick black marker line in middle)
1
Directions for preparing about 10 liters of the KMnO4 solution and standardizing it.
 Dissolve 24 grams of KMnO4(s) in 1 liter of deionized water
 Mix thoroughly and allow to stand overnight.
 Filter solution through porous glass or porcelain filter with suction. This process should
eliminate most of the insoluble residue.
 Dilute with an addition 9 liters of deionized water.
[Alternatively, if the KMnO4(s) is pure enough, the 24 g of solid can be dissolved in 10 L of
deionized water and mixed thoroughly without filtering]
 Standardize (titrate) against a weighed quantity (about 1 g) of primary standard grade of
Fe(NH4)2(SO4)2 . 6H2O
2 Directions


for unknown iron samples
These samples are available from Thorn Smith labs (7755 Narrow Gauge Rd, Beulah,
MI 49617)
Alternatively the unknown samples may be prepared by combining weighed quantities of
Fe(NH4)2(SO4)2 . 6H2O (primary standard grade) with weighed quantities of pure
(NH4)2SO4. **If this is done, samples must be thoroughly mixed and thoroughly ground
up with mortar and pestle to make each sample as close to homogeneous as possible.**
Instructor Notes
You will need to supply the balanced net ionic equation to students for this experiment (unless you teach
them how to balance redox equations in CHM 121, which I don't do until CHM 122). It is (w/o state
designations): 8 H+ + MnO4- + 5 Fe2+  Mn2+ + 5 Fe3+ + 4 H2O
Tell students to use about 1.5 g rather than 1.0 g of solid; otherwise volumes of titrant needed will be too
small. With 1.5 g of solid, a 13.1% Fe sample should take about 47 mL of 0.015 M MnO4-(aq) to reach
equivalence, and a 5.6% Fe sample should take about 20 mL.
NOTE: Over the past few semesters students in my section have consistently gotten lower than 13.11 %
for the 13.11% sample (range from 11.7 – 12.6%). Since the number of data points is low, please send
your students' results to me so I can see if that pattern continues.
CHM 121 Prep Sheet– Exp. 8 Verifying the
Absolute Zero of Temperature (Slowinski, 8th Ed.)
(for a class of 24 students working in pairs)
Each group will need a ring stand and a clamp (for holding the U-tube manometer), and possibly
glass stirring rods, all of which are available in the lab.
Other Special Equipment Needed (12 of each [one per pair]):










U-tube manometers (must be made)
1000 mL beakers
500 mL Erlenmeyer flasks, fitted with stoppers and glass tubing inserts (i.e., one-hole
stoppers with a glass-tubing insert whose width matches that of 8 mm OD rubber tubing).
These flasks must fit into the 1000 mL beakers!
pipet bulbs (simplest variety—used for siphoning only)
10” lengths of rubber tubing
24” lengths of rubber tubing
disposable pipets
meter sticks (Perhaps make an assembly in which the meter stick and U-tube are affixed
to a support? Dave is brainstorming this.)
digital thermometers
slotted one-hole stoppers (for clamping U-tube, unless semi-permanent assemblies are
made—see note after (8) above)
CHM 121 Prep Sheet – Handout Lab
The Air Bag Problem
(for a class of 24 students working in pairs)
Have plenty of 1-quart and 1-gallon Ziploc bags available (at least 24 bags in total; more quartsized ones than gallon). Also provide one or two l000 or 2000 mL plastic graduated cylinders, if
available, for general use.
1) NaHCO3 solid (can be store-bought baking soda, if cheaper), about 500 -1000 g total per class
(spread out in several smaller bottles)
2) 0.80 M H2SO4(aq), about 4-5 L per class (keep track for a couple of semesters to see if this is
overkill)
CHM 121 Prep Sheet – Experiment 14 A, B and C
Heat Effects and Calorimetry
(for a class of 24 students working in pairs)
Equipment:
 digital thermometers (12)
 7-oz Styrofoam coffee cups (24) [Note: manual calls for one 7-oz cup and one 9-oz cup per
pair, but two (nested) 7-oz cups works okay)
**Please do not use cardboard coffee cups or thin styrofoam cups—only use the
thicker "standard" styrofoam cups.**
 covers for coffee cups (12; plastic covers okay if Styrofoam not available--please look into
preparing Styrofoam covers for future year if not available currently)
 stirring rods/loops (12) [Note: currently using Cu wire to make rods with loops (see picture in
lab manual); glass would be better. Look into purchasing or making these for future.]
 Extra large sized (25 x 200 mm) test tube w/#3 stopper [Ignition Tube] (12)
Chemicals:
(1) A double set of 200 mL dropper bottles of 1 M HCl(aq)
(2) A double set of 200 mL dropper bottles of 1 M NaOH(aq)
(3) Student unknowns (Part A): Metals from Experiment 1 (Density). Each pair will need 50
grams of an unknown metal in the form of shot or small pieces which will fit through the
neck of a 25 mL Erlenmeyer flask. After use the metal needs to be recovered, cleaned by
rinsing with acetone, and dried on a paper towel. Appropriate metals include:
 Aluminum shot
 Lead sheet, 1/16”, cut into 1/2'' x
1/4" pieces
 Bismuth shot
 Lead shot
 Cadmium stick (sawed into slugs and split again)
 Tin shot
 Cobalt pellets
 Zinc shot
 Copper shot
(4) Student unknowns. Each pair receives a vial with 12-15 grams of one of the following
(purified grade, should be crystalline or powdered, not "caked"):
 NH4NO3
 CaCl2 (anhydrous) **In F'06, some vials with this reagent were so caked up that they
could not be scraped out with a large spatula! Addition of water did not
dissolve the bulk of the solid either. Need to investigate this further.
Perhaps store these vials in a dessicator, or try "baking" the caked salt in an
oven to re-dry? It is odd behavior considering that CaCl2 is supposedly
deliquescent—it should keep absorbing water until it dissolves into the
collected water. Not what seemed to be happening in those vials....**
 KNO3
 NaNO3
Instructor Notes: I have found that if stirring is done quickly using the digital thermometer
probe, no cap or stirrer is needed. The faster mixing perhaps makes up for the lack of a top.
CHM 121 Prep Sheet – Exp. 12 Alkaline Earths and Halogens
(for a class of 24 students working in pairs)
Students will need a supply of corks for 13 x 100 mm test tubes.
**Stock room note: Make sure that the hexane dropper bottles used for this experiment are NOT the
same ones as are used in the organic lab; on 10/17/06, a bleaching of Br2 color was observed and traced to
a contaminated hexanes bottle. [This has not been a problem as of late.]
Added in S’10: Please put all halogen / halide /hexane bottles (i.e., for Part B) in a hood so that students
won’t need to breathe the harmful vapors. Since we have two sets of bottles, I suggest putting the two
sets in two separate hoods. If the two sets of bottles for Part A (Group II cations) could be put on two
separate spots on the back bench, that would be ideal as well.
(1) Two sets of 200 mL dropper bottles for each of the following reagents. About 10 mL of each
solution will be needed by each pair of students. Prepare 150-200 mL of each solution for
each lab section.
 Barium nitrate, 0.1 M Ba(NO3)2
 Calcium nitrate, 0.1 M Ca(NO3)2
 Sodium bromide, 0.1 M NaBr
 Sodium iodide, 0.1 M NaI
 Potassium iodate, 0.1 M KIO3
 Hexane, technical grade is fine
 Sulfuric acid, 1.0 M H2SO4
 Strontium nitrate, 0.1 M Sr(NO3)2
 Magnesium nitrate, 0.1 M Mg(NO3)2
 Sodium chloride, 0.1 M NaCl
 Sodium carbonate, 0.1 M Na2CO3
 Chlorine saturated water, Cl2 in H2O
 Iodine saturated water, I2 in H2O
 Bromine saturated water, Br2 in H2O
 Ammonium oxalate, 0.25 M (NH4)2C2O4
(2) Student unknowns, 0.1 M of one of the following salts1. Each pair of students will need
about 10 mL of unknown salt solution.
 Strontium chloride
 Magnesium iodide
 Magnesium bromide
 Barium chloride
 Calcium iodide
 Strontium bromide
1
If the particular salt is not available, it can be prepared by mixing equal volumes of 0.2 M
Group 2A metal nitrate with 0.2 M Group 1A metal halide – e.g. 0.2 M Sr(NO3)2 + an equal
amount of 0.2 M NaCl.
Instructor Notes
**Stock room note: Make sure that the hexane dropper bottles used for this experiment are NOT the
same ones as used in the organic lab; on 10/17/06, a bleaching of Br2 color was observed and traced to a
contaminated hexanes bottle.
**Also try to figure out how to deal with the "degradation of stoppers" issue with Cl2 and Br2. Cracked
stopper cause a leakage on 10/17/06. Can we avoid dropper bottles for this experiment?
CHM 121 Prep Sheet – Handout Lab
What’s In These Bottles?
(for a class of 24 students working in pairs)
In this lab students are asked to identify which of six bottles contains specific solutions and
which of another six bottles contains other solutions. Students may request conductivity meters,
other specialized equipment or other chemicals.
Solution Key:
1A
NaOH
1B
HCl
1C
HNO3
1D
NaCl
1E
H2O
1X
Na2CO3
1F
AgNO3
1G
BaCl2
1H
NaCl
1I
Sugar
1J
H2O
1K
LiCl
2A
H2O
2B
HNO3
2C
Na2CO3
2D
HCl
2E
NaOH
2X
NaCl
2F
Sugar
2G
H2O
2H
AgNO3
2I
NaCl
2J
LiCl
2K
BaCl2
(1) One set of six dropper bottles labeled 1F-1K, and another set labeled 2F-2K. Each of these
bottles should contain a 5% solution (check with Dave—I think some of these may be 0.1
M, and the sucrose should be of higher concentration) of one of the following, according to
the key above:
 Silver nitrate, AgNO3
 Barium chloride, BaCl2
 Sodium chloride, NaCl
 Sucrose, C12H22O11
 De-ionized water
 Lithium chloride, LiCl
(2) One set of six dropper bottles labeled 1A-1E, and 1X, and another set labeled 2A-2E, and
2X. Each of these bottles should contain a 5% solution (check with Dave—I think some of
these may be 0.1 M) of one of the following, according to the key above:
 Sodium hydroxide, NaOH
 Hydrochloic acid, HCl
 Nitric acid, HNO3
 Sodium chloride, NaCl
 De-ionized water
 Sodium carbonate, Na2CO3
(3) Prepare a tray with the following chemicals for possible use by students. Be prepared for
students to ask for other miscellaneous solutions (mostly of salts)
Copper wire
Na2CO3(aq) (Exp. 18)
NaOH(aq) (Exp. 18)
Mg(NO3)2 (Exp. 12)
AgNO3(aq) (CHM 105, Exp. 10)
1 M H2SO4(aq) (Exp. 12)
BaCl2(aq)
Sugar (solid)
NaCl(aq)
Instructor Notes
CHM 121 Prep Sheet – Experiment 13
The Geometrical Structure of Molecules
(for a class of 24 students working in pairs)
Each pair of students will need a box of wooden ball and stick models. The instructor should
have a set of wooden ball and stick models as well as a set of Framework molecular models
(plastic tubes and jacks) to demonstrate the various shapes predicted by VSEPR.
Instructor Notes
This lab activity is best done following discussion of Lewis dot structures.
CHM 121 Prep Sheet – Experiment 17
Classification of Chemical Substances
(for a class of 24 students working in pairs)
Students will need to check for conductivity. Four working conductivity apparati on the
instructor’s desk for use by students should be sufficient. We do NOT currently have students
check for the conductivity of powdered solids (so no pennies, no insulated pliers, etc. are
provided).
(1) A double set of 200 mL dropper bottles of toluene – label as toluene
(2) A double set of 200 mL dropper bottles of absolute ethanol – label as absolute ethanol
(3) A double set of jars labeled I-VI, each containing about 100 grams (10-15 grams of each
solid are needed per section) of one of the following solids – naphthalene in Jar I, antimony
in Jar II etc.
 (I) Naphthalene, C10H8
 (II) Chunk antimony, Sb
 (III) Silicon carbide, 220 mesh
 (IV) Urea, H2NCONH2
 (V) Sodium nitrate, NaNO3
 (VI) Barium chloride hydrate, BaCl2 . 2H2O
(4) Student unknowns. Each team of students receives two vials (numbered 1 and 1A, 2 and 2A
etc.) each containing a different unknown, paired as listed below, and rubber banded
together.
 Silicon pieces and naphthalene (try benzophenone?)
 Na2CO3 and benzoic acid
 Silicon dioxide and CaCl2
 NaCl and powdered Fe
Instructor Notes
Because we do not test conductivity in powders, you cannot distinguish between covalent
network solids and powdered metals (of high melting point). You also cannot unambiguously
distinguish between insoluble ionic compounds of high melting point from covalent network or
powdered metals (of high melting point).
CHM 121 Prep Sheet – Experiment 19 (Parts A and B only)
Molar Mass Determination by Depression of the Freezing Point
(for a class of 24 students working in pairs)
Students will need crushed ice.
Equipment:
 digital thermometers (12)
 12-oz Styrofoam coffee cups (24)
NOTE: These are larger than the cups for Experiment 14
**Please do not use cardboard coffee cups or thin styrofoam cups—only use the
thicker "standard" styrofoam cups.**
 Buchner funnel top pieces only (these should fit nicely on top of the Styrofoam cups so that
students can pour their ice/solution mixture into it and filter out the ice)
Chemicals:
(a) Student unknowns (Part B): Each pair should be given about 20 mL of one of the following:
(1) methanol
(2) ethanol, 95% or anhydrous
(3) 2-propanol
Instructor Notes:
 Students must stir solutions quite rapidly and for longer than they expect in order to get the
greater than 4-degree depression mentioned in the manual.
 Students should use more ice than water, and not fill up the cup more than 2/3 full in order
to end up with the approximately correct amount of liquid water. If they have too much
water, the temperature decrease will not be as large as they are told it will be.
The following experiments have been removed, at least for now.
Note, however, that the materials for the flame testing (or at
least some of them) will likely be used for demonstration and for
the “bottles” lab
CHM 121 Prep Sheet – Handout Lab
Atomic Emission/Electronic Structure
(for a class of 24 students working in pairs)
A couple of white light sources and some diffraction gratings should be available for students to
check out the dispersion of white light into a rainbow of colors. Also have out about 4-5 gas
discharge tubes with spectrophotometers for demonstration of atomic emission spectra. Two of
the gas discharge tubes should be of hydrogen
(1) Cotton balls – 30-50 per section
(2) Plastic blocks with six wells – twelve per section
(3) Jars, labeled only as 1-6, each with one of the following salts – 5-10 grams of each salt per
section
 Barium chloride, BaCl2
 Calcium chloride, CaCl2
 Lithium chloride, LiCl
 Potassium chloride, KCl
 Sodium chloride, NaCl
 Strontium chloride, SrCl2
Instructor Notes
CHM 121 Prep Sheet – Handout Experiment
Experimentally Determining the Ideal Gas Law Constant “R”
(for a class of 24 students working in pairs)
NOTE: Make sure that there are ample clamps that can be turned at an angle. Many of the
newer clamps at DP are at 90 degrees and are not adjustable.
Equipment:
 "thistle tube assembly" pieces; see picture below; each consists of:
a) a double-holed stopper that fits a 250 mL Erlenmeyer flask, with glass tubing threaded
through each hole as shown—one has an "L" or "V" bend of about 75 and the other is
a straight tube that goes nearly to the bottom of the Erlenmeyer flask
b) a one-holed stopper threaded on the "V" bend piece; this stopper should fit the large
test tubes in student drawers.
 pieces of rubber tubing to attach to the OTHER glass tube on the assembly (3/16" x 1/16"
rubber latex; probably about 15-20 inches in length each). Each piece of rubber tubing
should have a buret tip (or short piece of glass tubing) inserted on one end
Chemicals:
 KClO3/MnO2 mixture (30-35 g per class); Prepare by mixing 5-10% of the MnO2 into the
KClO3 powder and mixing