CHEM& 151
Winter 2009
EQUIPMENT, MEASUREMENT, DENSITY, AND
GRAPHING
Prelab attached (p. 17-18)
Fill-in - Refer to your Laboratory Procedures handout for how to do your fill-in lab reports.
Name _____________________
Stamp Here
Lecture Instructor
Partner ___________________
_____________
Date ______________________
Have you attached the graphs and the conclusion?
INTRODUCTION
Any comprehensive course in chemistry must include a certain amount of laboratory time. In a
chemistry laboratory, you will learn how to develop proper lab techniques, carefully observe
experimental results, and accurately interpret data to arrive at a desired solution to a chemical
problem. The laboratory also allows you to observe how the chemical principles and theories
presented in lecture apply to real life situations. The development of good laboratory techniques is
essential in obtaining precise, accurate experimental results. It is, therefore, important to develop
these skills early in the quarter.
The measurement of the physical properties of pure substances is a very important technique as a
part of the larger scheme of identifying elements and compounds.
This first experiment will introduce you to:
A. Significant Figures
B. Finding Equipment in the lab
C. Proper methods for performing volume and mass measurements.
D. Methods of measuring and calculating density of an unknown solid by volume displacement.
E. Density and graphing
F. Good graphing techniques (important for all lab reports)
SECTION A: SIGNIFICANT FIGURES
Each time you make a measurement, you must pay attention to the markings (divisions) on the
measuring device to determine how many digits (significant figures) to record in your answer.
Correct use of significant figures is important throughout this remainder of this experiment and all
subsequent experiments.
Significant figures in your measurements:
• Digital instruments (example balance): record every digit given. For example,
if the balance readout looks like this, record 1.70g, not 1.7g.
•
1.70
Manual instruments: always include an estimated digit. For example, using the centimeter ruler
in Figure 1, the pencil might be recorded as having a length of 1.87cm. In this number, the “7” is
the estimated digit. Another acceptable reading would be 1.88cm, but any other number of
significant figures (or number of decimal places) would be incorrect. For example, 1.9cm would
be an incorrect reading.
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0
1
2
3
4
5
Figure 1. Pencil image from the Yale University Picture Dictionary.
http://berlin.cls.yale.edu/picturedictionary/pub/word.asp, accessed 2-21-07.
Significant figures in measurements that someone else has made:
• All non-zero numbers are significant
4.56cm includes 3 s.f.
•
Zeroes between non-zero numbers are significant
10.77mL includes 4 s.f.
•
Leading zeroes are never significant
0.01077L includes 4 s.f.
•
Trailing zeroes are significant in the presence of a decimal place
123.70g includes 5 s.f.
120.0mL includes 4 s.f.
•
Trailing zeroes in the absence of a decimal place are ambiguous, and are generally assumed to be
non-significant unless more information is available. It is best, in this situation, to write the
number in scientific notation, this ensures no ambiguity regarding the number of significant
digits in the number.
2300g might have 2, 3, or 4 s.f.
To correctly indicate the number of sig figs in this number, put it in scientific notation:
2.300x103g includes 4 s.f.
2.30x103g includes 3 s.f.
2.3 x 103g includes 2 s.f.
Significant figures in calculations:
• Multiplication and Division: the result is rounded to the same number of significant figures as
the least precise number in the calculation:
 0.70g 
5.67 mL × 
 = 3.969g ⇒ round to 4.0g (2s.f.)
 mL 
•
Addition and Subtraction: the result is rounded to the same number of decimal places as the
least precise number in the calculation:
121.0g - 4.34g = 116.66g ⇒ round to 116.7g (round to tenths place): the least precise
number is only known to the tenths place, so the answer can only be reported to
the tenths place.
•
When you perform a series of calculations, round after each different operation, perform
addition and subtraction: get the answer to the correct number of significant figures. Then
perform multiplication and division. It is important to remember, that you can gain or lose
significant digits when you add and/or subtract numbers together!
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Precision: A measurement with a greater number of significant figures is more precise than a
measurement with fewer significant figures. (For example, 5.0g is more precise than 5g)
Accuracy: Accurate measurements are correct measurements. A digital watch, for example, might
have a high degree of precision and measure hundredths of seconds, but if it’s running ten minutes
late, it is not accurate.
B. FINDING EQUIPMENT IN THE LAB: A SCAVENGER HUNT
While we encourage everyone to have a lab partner, this section will serve you better if it is
completed independently. If you do have a partner, make sure that each person looks around the lab
and participates in finding the items in the “scavenger hunt”. You need to find the items listed
below (they will be located in a variety of places around the lab!), and place them on the bench-top
in front of you in the order listed. After you have found all of the items, ask the lab instructor to
check off on your items. Once the instructor has given his/her approval, you should return the
items back to the appropriate place in the lab (note: some of the items you will need for the next
section, so read that and keep those items at your bench-top. Those can be returned after you finish
the rest of the experiment!)
 By instructor
_______
_______
_______
_______
_______
_______
_______
_______
_______
_______
_______
_______
Item
Utility clamp
Buret Clamp
Buret
50-mL beaker
125-mL Erlenmeyer flask
Thermometer
Tongs
Ring stand
Test tube
Spatula/scoopula
Graduated pipet
Graduated cylinder
Instructor Initials:
__________________
C. VOLUME AND MASS MEASUREMENTS (Refer to the appropriate sections in the in the
Laboratory Handbook for information about using measuring devices.)
Discussion of Volume Measurements
Almost all chemical experimentation requires accurate measurement of some physical or chemical
property. In this section of the experiment you will learn to use the buret, the graduated cylinder, the
graduated pipet, and the beaker as a means of measuring the volume of a liquid. The precision and
accuracy of the three methods of measurement will be compared using water as the liquid. Water is
attracted to glass, so instead of forming a flat surface, it forms a concave surface (curves upward at
the outer edges) so all volume measurements should be made at the bottom of the curved surface
when using glass devices. This curvature is called the meniscus.
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Figure 2 shows the correct eye position to use when reading the volume. Incorrect positioning
(called parallax) can result in a volume measurement that is either too large or too small. The
correct reading of this volume would be 82.0 mL.
Typically, precision is defined as the reproducibility of the results, or how many decimal places you
can measure with a particular device. If your answers are grouped together and you can get the same
reading each time, your results are precise. Accuracy is how close your value is to some “true
value”. In some cases we need to use an average instead of a “true value”. The following is a set of
data collected by one student of the length of a particular object: 42.56 cm, 42.55 cm, 42.58 cm. The
class average when 10 students took 3 measurements each using the same type of measuring device
was 42.12 cm. This person made very precise measurements, but the results were not very accurate
when compared to the class average.
Beakers
Beakers are designed to give an approximate volume measurement. They come in
a variety of sizes ranging from those which will hold only a few mL to others
which hold many liters. You will use many of these sizes in lab. The precision
and accuracy of the measurement depends on the size of the beaker, but the
measurement is never more precise than a whole number value (i.e., 40 or 45
mL, never 45.3 mL). Beakers have a large width as compared to height (see
Figure 3) which adds to the difficulty in precisely and accurately reading the
volume measurement. Beaker volumes are always whole number readings.
Figure 3: a
typical beaker
Graduated Cylinders
Graduated cylinders are designed to deliver a volume of liquid. While
graduated cylinders also come in a variety of sizes, you will use primarily
the 10 mL and 50 mL sizes in lab. The precision of the volume
measurement is estimated to one tenth of the smallest division shown on
the cylinder. This will give you an additional estimated decimal place
(example 45.3 mL, never 45 mL). Most graduated cylinders in the lab
can be read to the tenths place ( + 0.1 mL)
Graduate cylinders are considerably smaller in width than in length (see
Figure 3) so the meniscus can be more easily seen and the spacing between
marks on the scale is larger.
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1-2 cm in width, 15-30
cm in length
Graduated Cylinder
Figure 4
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Buret
The buret is also designed to accurately deliver a volume of liquid. In other words, you are
measuring the amount of liquid removed from the buret. You will be using a 50 mL buret in lab.
The buret has a very small width compared to length (see Figure 5a and b) allowing for easy reading
of the meniscus, and therefore, the volume. The buret volume can be measured to the hundredths
place ( + 0.01 mL).
Liquid is drained from the bottom of the buret. Numbering of the buret, therefore, starts at the top of
the buret. Volume readings are made by (1) filling the buret to the 0.00 mL mark (first reading
located at the top of the buret) or some initial volume, (2) drawing off the desired volume of liquid,
(3) measuring the new volume reading on the buret and, (4) subtracting the initial buret reading from
the final reading to obtain the delivered amount of liquid.
Figure 5a and 5b: typical burets
Pipets
Pipets (Figure 6) come in many sizes and many shapes, but if they are used for precise and accurate
measurement, they are made out of glass. Plastic pipets are disposable and are used only when exact
volumes of liquids are not required. The pipet is designed to deliver a volume of liquid by gravity.
Liquid is sucked into the pipet using a pipet bulb. The pipet is immersed in the liquid. The bulb is
squeezed to expel air, then gently, but firmly placed over the top of the pipet (the pipet is never
inserted into the bulb). By slowly and carefully releasing the pressure on the bulb, liquid will be
sucked into the pipet. The appropriate amount of liquid is obtained and a finger (thumb or forefinger) is placed over the top of the pipet to hold the liquid at a certain volume, then the liquid is
dispensed by gravity into the appropriate receptacle. The last bit of liquid is never “blown” out of
the pipet by the bulb. The pipets are all calibrated to leave a small amount of liquid behind. Pipets,
just like burets, must be read to the hundredths place.
Figure 6: Volumetric and graduated glass pipets
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Procedure: This section should be completed with a partner – meet someone new and partner up!
Obtain two 100 mL beakers. Fill one of the beakers (called the stock beaker) with ~ 50 mL of water.
Set the other beaker aside. Obtain a 10.00 mL pipet, a 10.0 or 25.0 mL graduated cylinder, and a
buret. You will perform the same procedure 4 times, using a different piece of measuring equipment.
Review the glassware section of this laboratory handout to remind yourself about significant
figures and measuring using these pieces of glassware.
Many times it is also necessary to measure the mass of a liquid or solid. You will use an electronic
top-loading balance to perform these measurements. These balances can be read to + 0.01 grams.
When you use any balance be sure to record your data to the appropriate number of significant
figures, even if they are zero (20.00 g not 20 g).
Part 1: The beaker
Mass the dry beaker, record this mass under the starting mass of the beaker for the beaker
portion of the experiment. Using the stock beaker, which you previously filled with ~ 50 mL
of water, pour 20-30 mL of that into your pre-weighed dry beaker.(Note: you do not need to
measure exactly twenty milliliters, but you do need to record the exact volume.) Record the
volume of the water in the beaker exactly (with the correct number of significant figures –
see your prelab!) in the table below. Mass the beaker and the water. Record the mass of the
beaker and water in the data table in the beaker portion of the experiment. Pour the water out
of the beaker, and dry the beaker with a paper towel. Repeat for trial 2.
Part 2: The pipet
Re-mass the dry beaker, record the mass of the beaker in the table below. Pipet 10 mL of
water from the stock beaker. Again, you need not get exactly 10 mL but you should record
the actual volume of water you placed in the pipet with the correct number of significant
figures. Drain the water from the pipet into the dry beaker (remember not to blow out the last
little bit!). Mass the beaker with the water and record the mass in the data table below. Pour
out the water and dry the beaker with a paper towel. Repeat for trial 2.
Part 3: The graduated cylinder
Re-mass the dry beaker, record the mass of the beaker in the table below. Fill your graduated
cylinder with 20-30 mL of water. Again, you need not get exactly 20 mL of water but you
should record the exact volume of water in your graduated cylinder with the correct number
of significant figures (see the pre-lab!). Pour the water from the graduated cylinder into the
dry beaker. Mass the beaker with the water and record the mass in the data table. Repeat for
trial 2.
Part 4: the buret
Re-mass the dry beaker, record the mass of the beaker in the table below. Fill your buret with
water. You need not fill the buret all the way to the 0.00 mL mark, but fill it with a
substantial amount of water. Open the stop-cock to drain out some of the water which will
fill the tip of the buret. Close the stop-cock. Record the starting amount of water in the buret
(simply read the location of the meniscus) with appropriate significant figures. Record the
starting volume in the data table. Open the buret to dispense 15-30 mL of water directly into
the dried, pre-weighed beaker. Again, you need not get exactly 15 mL of water but you
should record the final volume of water with the correct number of significant figures. The
amount of water dispensed by the buret = final volume measurement – initial volume
measurement. (example: if you filled the buret and read the initial volume at the meniscus it
reads 0.55 mL. You dispense a volume of water – you want it to be around 15 mL. You
open and then close the stop-cock. Your final volume reading of water at the meniscus is
18.12 mL. The total volume dispensed by the buret = 18.12 – 0.55 mL = 17.57 mL)
Don’t forget – each piece of glassware is used twice – record data in the table on the next page.
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Data
include units with
each number
mass of dry
beaker
volume of water
mass of
beaker +
water
mass of water
(calculation)
density of
water
(calculation)
Beaker: Trial 1
Beaker: Trial 2
Pipet: Trial 1
Pipet: Trial 2
Graduated
Cylinder: Trial 1
Graduated
Cylinder: Trial 2
Buret: Trial 1
Buret: Trial 2
Starting volume:
___________
Ending volume:
____________
Total volume:
____________
Starting volume:
___________
Ending volume:
____________
Total volume:
____________
Calculations: For each step, calculate the mass of the water that you added. Then use the mass of the
water and the volume of the water to compute the density, given that density = mass/volume. Show
your calculations in the table above where needed
Before going any further – obtain instructor initials _______________________________
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Questions:
a. Which volume-measuring device was easiest to use?
b. For each piece of glassware, calculate the average density. Show all your work: (don’t
forget units!) **hint: perform addition first to determine correct number of sig figs
Beaker: average density of water =
Pipet: average density of water =
Graduated cylinder: average density of water =
Buret: average density of water =
c. A reasonable assumption given the water’s temperature is that the density of water is 0.998
g/mL. For each of your devices, compute the percent difference between your average
density value for each piece of glassware and the true density. Show your work and pay
careful attention to the significant figures when you perform the subtraction!
your value - "true"value
x 100 = % difference
"true" value
Beaker:
Pipet:
Graduated cylinder:
Buret:
d. Which device was most accurate? Which was most precise? Explain.
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D. DETERMINATION OF THE DENISTY OF AN UNKNOWN
Discussion of Density Determinations
Density is defined as mass per unit volume. In this experiment you will use three different methods
for determining density. In Part I the two methods will be for solids. Be sure to record object
identification codes and shapes for the solids. Part II will be used for a liquid.
Solids
It is possible to determine the density of a solid that fits the category of having a regular geometric
shape such as: cylinder, sphere, rectangle, and cube. Two techniques will be used to measure the
volume of each solid object.
The first method will involve using a Vernier caliper to determine the dimensions of the object in
units of centimeters, calculating the volume from the appropriate equation.
Vsph =
4 3
πr
3
Vcyl = π r 2 h
Vrect = l ⋅ w ⋅ h
The second method requires the use of a graduated cylinder filled to a calibrated level with water to
measure volume by the displacement of water. The difference in the volume of water originally and
the volume with the solid is the volume of the solid alone.
Liquids
In Part II you will employ the techniques of graphing to determine the density of water. You will
collect at least five sets of volume and mass data, record this data as shown in Part E, and then graph
this data using the graphing techniques of Part F to find the density of water.
EXPERIMENTAL SECTION
I. Density of a Solid
Do all your mass measurements on only one Electronic balance – use the same balance for all
mass measurements. Obtain one solid sample from the reagent bench and determine its density
using both Methods.
Procedure, Method 1: Record the data in the table below/next pg.
1. Using the Electronic balance, determine the mass of the solid.
2. Using your Vernier caliper, measure the dimensions of your solid and determine its volume.
3. Calculate the density of your solid.
Method 1- Solid Density
Object Identification (letter tapes on the solid sample)
Object shape
Mass, Electronic balance
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Volume via dimensions (Label values with units and appropriate number of significant figures.
Formulas for volume are on pg. 9.) You must get instructor initials for your measurements before
you perform your calculations
diameter of the cylinder =
height of the cylinder =
Instructor initials for measurements
________________
Calculations for volume of the cylinder:
Volume of object
Calculations for density of the cylinder:
mL Density of object
g/mL
Procedure, Method 2: Record the data in the table on the next pg.
1. Add roughly 30 mL of water to your 50 mL graduate cylinder and then carefully record the
volume to the proper precision.
2. Add the solid to the graduate cylinder. This should be done by tilting the graduated cylinder
at an angle and allowing the solid to slide down into the cylinder. If you simply drop the
object into the graduated cylinder you will either break the graduated cylinder or splash water
out, which makes your volume measurement inaccurate. Make certain that the measured
volume of water will completely cover the immersed object and that the graduated cylinder
used is large enough to produce measurable results.
3. Using the mass of the solid from Method 1, calculate the density of your solid.
Solid Density, Method 2.
Volume via displacement
initial volume of water
________ mL
volume with object and water
________ mL
Calculations
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Volume of object:
mL
Density of object:
g/mL
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Questions:
1. Look carefully at your object and see if you can identify it; note any symbols on it (Zn, Cu, Al,
etc). If you find no clues, ask your lab instructor to help identify your solid. Then look up its
accepted value for the density in the Handbook of Physics and Chemistry, and determine the
percent difference for both Method 1 and Method 2 using the formula explained previously.
True value of density for my unknown object __________________________
% difference calculations: show your work! – pay careful attention to sig figs especially while
performing the subtraction!
Method 1.
Method 2.
2. Describe in words how your results for both methods compare with the accepted value.
3. Calculate the average density using the values from Method 1 and Method 2. List a possible
source of error between your average experimental value and the true value. Explain how it
affected your value.
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SECTION E: DENSITY AND GRAPHING
This section will give an example of how to record the data in tabular form. Tables are easier for
you to write, easier for your reader to read, and easier to understand, than data in narrative
form. For this experiment, a suitable Data section is included. Labeling of all data and units for
data must be included.
Density of a Liquid (Water)
Procedure
1. Obtain a clean dry 100- mL beaker. Weigh it and record the mass in the table below (page 13).
2. Fill the buret with distilled water, taking care that there are no trapped air bubbles. Open the
stop-cock to fill the tip. Close the stop-cock, add more water to the buret if needed. Record the
volume to the nearest 0.01 mL (or set it at 0.00 mL). Be sure the tip is filled with water!
3. Draw off between ~3.00 - ~7.00 mL of water into the pre-weighed l00 mL beaker; record the
total volume drawn from the buret to the nearest 0.01 mL. Do not spend time adjusting the
volume to a specific number, simply write down the volume you dispensed.
4. Determine the total mass of the beaker and water by weighing on the same electronic balance as
your original beaker was weighed; record the mass to the nearest 0.01 g.
5. Without emptying the water from the beaker, repeat steps 2 and 3 at least 4 more times (a total
of 5).
6. Record the data to be used on the graph in a table as shown. Graph your results using the
techniques of Part F. Always use graph paper.
7. After you have graphed the data, determine the slope of your line using arbitrary x and y (xn, yn),
(xm, ym) coordinates as the points of reference; do not use data points. Be sure to use the proper
units in your answer, and show formulas and substitutions in your solution process. Show work
and calculations on your graph.
m =
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∆y
=
∆x
(y
(x
)
- x )
m
- yn
m
n
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= slop e
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Data Table for Liquid Density. (use the space provided in the volume column to perform
difference calculations to determine the total volume of water added from the buret into the beaker)
Buret
drawing
Cumulative volume dispensed (mL)
(total volume of water in the
beaker), x-axis
Cumulative Mass of
Water + beaker (g), y-axis
0
Initially there is 0.00 mL of water
in the beaker
_____________ grams
1
TOTAL volume: __________ mL
____________ grams
2
TOTAL volume: __________ mL
____________ grams
3
TOTAL volume: __________ mL
____________ grams
4
TOTAL volume: __________ mL
____________ grams
5
TOTAL volume: __________ mL
____________ grams
Remember: the total volume will be the overall cumulative volume of water that is in the
beaker after each addition of more water – NOT individual volumes – total volume!
You will plot the above data by hand on the graph paper provided (pg 15). Please review prelab question 3 and re-read the good graphing techniques (part F, pg 14)!
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F: GRAPHING TECHNIQUES (Also refer to the section on “Representing Data and Results
Using Graphs” in your Laboratory Handbook where there is an example.) You need to employ the
techniques of graphing to determine the density of water from the data you collected in Part E. You
will plot your data on graph paper, putting total volume on the x-axis (abscissa) and mass on the yaxis (ordinate), remembering the following graphing techniques:
1. Label each axis with the type of measurement it represents and the type of units used, e.g.,
volume in milliliters, and mass in grams. Always label so that numbers increase toward the right
on the x-axis and upward on the y-axis.
2. Choose a size of graduation so that your data will spread over as much of the entire graph as
possible. The graduations on the two axes need not be of the same magnitude, but the
magnitude of a given graduation along one axis must not change.
3. Number the graduations on each axis. It is not always necessary to start with the origin being
zero (for the volume measurement in this experiment use 0; begin the mass graduations at
about 10 grams less that your first mass reading).
4. When locating a point on the graph, it is a good practice to circle the small point with a small o,
rather than use large dots or x's.
5. When drawing the line on a graph, always draw a smooth line using a ruler through the average
location of the points, rather than connecting the points in a “draw by numbers” method.
6. When extrapolating a curve (extending the curve beyond the range of the actual data points),
continue the curve using a dotted line rather than a solid one, to distinguish it from the part of
the curve based on actual data.
7. Show all data and calculations for the slope on the graph itself. Indicate the arbitrary (not
data) points used for the slope and indicate the y-intercept where appropriate. Do not use actual
data points in your calculations!!! Use two points that are on that are on the best-fit line and
that are within the range of your data.
8. Make sure that all axes are labeled with the quantity and the units, and that the graph has an
appropriate title. Y vs. X is NOT an appropriate title. Your title should be a descriptive
“sentence” that tells the reader what the point of the graph is. Why did you plot y vs. x? What
information does it give to the reader?
Remember, you spent valuable time collecting this data. Make the graph
large enough (the data should take up the WHOLE page) so that it can be
read accurately and so that you can draw your line, calculate slopes, and
find the intercepts with some precision.
Please use the graph paper on the next page.
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Final Graph: Part E
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Questions: (Show all calculations on your graph or as appropriate in the question – review
pre-lab question 3 if you need help)
1. What do scientists call the physical property represented by the slope of your line? Hint: what
would the units of the slope be?
_____________________
2. What numericalvalue did you find for this property, give units as well?
_____________________
3. Extrapolate your graph past the y-axis. What is the mass at zero volume? Estimate this value
from your graph to as many significant figures as your graph allows!
_____________________
4. This mass represents the mass of what object? (Do you realize that you have just determined the
mass of an object without weighing it directly?)
_____________________
5. The known density of water at 20°C (approximate laboratory temperature) is 0.998 g/mL.
Calculate the percent difference for the density of water that you obtained from the slope of your
graph, versus the known density. Show your calculation – pay attention to sig figs!!
_____________________
6. Calculate the percent difference for the mass obtained from y-intercept in comparison with the
mass of the beaker as weighed in step 1 of the procedure. Show your calculation
_____________________
7. Write a concluding paragraph on a separate sheet of paper restating your results and possible
errors, regarding this section (E). Follow the format for the concluding paragraph in the example
formal report. Use complete sentences. Do not use personal pronouns in your concluding
paragraph!! Attach the paragraph and your graph to the end of this report.
Have you attached the conclusion?
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Basic Equipment
Stamp:
Prelab Questions: These questions are to be answered before you come to the laboratory.
Always read the experiment before starting the prelab. Your textbook, Lab handout (this
packet) and the Laboratory Handbook are excellent resources. It is your responsibility to get
this stamped by the Lab Instructor before you begin working on the experiment!
1. How many digits after the decimal place can you read a (circle one):
a) beaker
0
1
2
3
b) graduated cylinder
0
1
2
3
c) buret
0
1
2
3
d) pipet
0
1
2
3
2. You have a sample of titanium metal. You mass it on an electronic balance and it has a mass of
7.52 grams. You decide to measure the volume by volume displacement. You fill a graduated
cylinder with 35.2 mL of water. After dropping the titanium into the graduated cylinder, the
volume now reads 36.9 mL. Determine the density of titanium:
Density =
If the density of titanium is 4.51 g/mL, what is the percent difference between your value for density
calculated above and the accepted value for the density? Show your calculations. (see formula on pg
8)
percent difference =
3. Using the following data to graphically find the density of a substance. Graph the data by hand,
on the graph paper on the back of this page. Draw a best-fit line through the data and determine
the slope of this line. Make sure that you label the axes and title the graph appropriately. Show
this graph to the Lab Instructor. FOLLOW THE GOOD GRAPHING TECHNIQUES (pg 14)
Total Volume dispensed
(mL) [x-axis]
13.25
22.98
33.15
42.67
Cumulative Mass of substance + beaker
(g) [y-axis]
48.67
55.35
66.37
72.15
density =
#2 Basic Equipment
Rev W09 AEM Winter 2009
Page 17 of 18
Pre-lab Graph
#2 Basic Equipment
Rev W09 AEM Winter 2009
Page 18 of 18