Measurement in the Laboratory
Name Abby Hanson, Deidre
Hooley, Taylor Woodhouse
Chemistry Lab #1
Date 9/29/2010
Purpose: to practice making accurate quantitative measurements in the laboratory.
Procedure: We will conduct six experiments to practice the measurement of length,
temperature, mass, volume, density, and concentration. We will use a variety of
objects to measure, including rulers, graduated cylinders, and scales. We will strive
to accurately measure the substances we are given. We will wear goggles. In part
one, we shall measure a textbook using a standard metric ruler. In part two we will
measure the volume of a test tube filled with water by pouring the water into a
graduated cylinder. Also we will find the volume of a metal screw by finding how
much water it displaces. In part three will find the mass of 100ml of water by
weighing it in a plastic cup then subtracting the mass of the cup. Using the same
method we’ll find the mass of the screw.
Prelab Questions:
1. What instruments may be used to measure each of the following quantities?
a. Length: rules
b. Mass: scale
c. Volume: graduated cylinder
d. Temperature: thermometer
2. What is density?
-mass divided by volume, or the amount of matter in an object
3. Does color affect heat absorption?
-Yes. Some colors, i.e., black, absorb and hold heat better than others, rather
than colors like white that reflect heat instead of holding it.
4. How might the concentration of a substance affect its ability to harm an
organism?
-The more of a harmful substance you ingest/are exposed to the more
likely you are to be harmed/affected by it.
Results:
Observations: (General descriptions of visible appearances or changes that occur
during the experiment, such as “table salt is a white, cube-shaped crystal which dissolves
in water. (Qualitative))
Data:
Part 1: Measuring Length
1
Textbook Measurement
Dimension
Millimeters (mm)
Centimeters (cm)
Length
220.1
22.01
Width
35.9
3.59
Height
276.8
27.68
Part 2: Measuring Volume
Test Tube Measurement
Milliliters (ml)
Microliters (l)
29.0
29,000
Substance
Water
Meters (m)
.2201
.0359
.2768
Liters (l)
.029
Pipet Measurement
Number of Drops in 1 ml
22
Substance
Water
Screw Measurement
Final Water Volume
Water Displaced
(ml)
(Volume of screw) (ml)
50.19
.19
Initial Water Volume
(ml)
50.00
Part 3: Measuring Mass
Mass of Cup (g)
9.41
Water Measurement
Mass of Cup and Water (g)
Mass of 100 ml of Water
108.36
98.95
Mass of Screw (g)
7.52
Part 4: Measuring Density
Substance
Water
Salt Water
Isopropyl Alcohol
Density Measurement
Mass
Mass of
Mass of
of Cup
Cup and
Liquid
(g)
Liquid (g)
(g)
9.39
58.94
49.55
9.39
64.86
55.47
9.39
51.49
42.1
Volume of
Liquid
(ml)
50.0
50.0
50.0
Density of
Substance
(g/cm3)
.991
1.11
.842
Part 5: Measuring Temperature
Temperature Measurement
2
Time
(minutes)
Initial
2 minutes
4 minutes
6 minutes
8 minutes
10 minutes
___15__
minute
(cooldown)
Black Sand Temperature (C)
22.5
23.0
23.5
24.1
24.5
24.9
23.9
White Sand Temperature (C)
21.7
21.5
21.7
22.0
22.2
22.5
21.5
Part 6: Measuring Low Concentrations of Water Pollutants
Solution
Blue food dye (10%)
Cup 1
Cup 2
Cup 3
Cup 4
Cup 5
Concentration (ppm)
10
1
.1
.01
.001
.0001
Calculations: Screw Measurement: 50.19ml-50.00ml= .19ml
Water and Cup: 188.30g-9.41g= 98.95g
Density: D=m/v=49.55g/50.0ml=.991g/ml
Conclusion: We measured a textbook, found the volume of water and a screw using a
pipet and a test tube, the mass of a screw, the density of water, salt water, and isopropyl
alcohol, the temperature of sand over a period of time, and the concentration of food dye
in water. Skills were learned that we will use in every other lab throughout the rest of the
year. A better understanding of how to work through a lab and make accurate
measurements was achieved.
Discussion of Theory: See Turnitin.com
Experimental Sources of Error: There could be many things involved for
experimental sources of error. The numbers could have been rounded wrong,
causing them to be bigger or smaller then they actually were. The tools could have
been used improperly, and therefore caused a different amount. Also reading the
scale, the ruler, and the graduated cylinder improperly could have caused error. The
part if the lab that gave us the most experimental error was the concentration. The
pipet was difficult to get the correct amount of water in, which caused the amount of
water in the cups to be off.
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Post Lab Questions:
1. Convert the length measurements of the textbook in Part 1 to volume by
multiplying the length, width, and height. Record the answer in cubic
centimeters.
- V=lwh
22.01 cm  3.59cm  27.68cm
2187cubic centimeters
2. In part 3 the mass of 100 ml of water was determined. Using this
information calculate the density of 100 ml of water.
- D= m/v
D= 98.95g/ 100mL
D= 1 g/mL
3. How does this density compare to the density of 50 ml of water calculated in
Part 4?
- They are closely related, because .991 can be rounded to 1, which
is the approximate density of rounded.
4. Which liquid in Part 4 had a density greater than water? Less than water?
- Salt water has a greater density than water. Isopropyl alcohol has
a density less than water.
5. In Part 5, the temperature of two different colors of sand, black and white,
were compared under a lamp. Using the data table/worksheet, graph the
temperature values for the 10-minute exposure of each color of sand. (Note:
Graph both sand colors on the same graph using a different color pencil for
each.)
6. Did one color of sand lose heat faster than the other color after being allowed
to cool for 15 to 20 minutes? Explain.
7. Would it make sense to wear lighter colored clothing in the winter or in the
summer based on this data? Explain.
8. What happens to the color of the dye in Part 6 in each successive medicine
cup?
- The color got lighter as the concentration level became lower.
9. Convert the final concentration of cup 5 in Part 6 into parts per billion (ppb)
and parts per trillion (ppt).
10. What other quantitative measurements may be taken?
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