# Explain why the metric system is used in science.

Lab 3 Data Analysis & Graphing CHEM101L

Student Name:

Access Code (located on the lid of your lab kit):

Pre-Lab Questions:

1. In your own words, describe how to calculate density.

2. Explain why the metric system is used in science.

3. In any given experiment, how is it possible for your experimental technique to be both accurate and precise?

4. If you are changing m to cm, what direction do you move the decimal point?

Experiment 1: Metric Measurement Lab Table 1: Length of Materials

 Material Meters (m) Centimeters (cm) Millimeters (mm) Kilometers (km) Diameter of penny Height of counter/table Width of textbook Length of room

Table 2: Mass of Materials

 Material Grams (g) Centigrams (cg) Milligrams (mg) Kilograms (kg) Mass of a penny Mass of empty 10 ml graduated cylinder Mass of 10 mL graduated cylinder with 10 mL water Mass of a pencil

Table 3: Volume of Materials

 Volume Liters (L) Centiliters (cL) Milliliters (mL) Kiloliters (kL) 2 mL 5 mL 6 mL 9 mL

Post-Lab Questions

1. In the metric system what unit of measurement is used for volume?

1. Describe the table that you measured and how the measurement was conducted.

1. Why were you asked to use a 10 mL graduated cylinder to measure volume instead of a 250 mL beaker?

1. Describe the room you measured and how the measurement was conducted.

Experiment 2: Density of a Gummy Bear

Table 4A: Day 1 Mass Data

 Materials Grams (g) A. Weight of Paper Towel B. Weight of Paper Towel with Gummy Bear Weight of Gummy Bear (A-B) *Record this Value in Table 5

Table 4B: Day 2 Mass Data

 Materials Grams (g) A. Weight of Paper Towel B. Weight of Paper Towel with Gummy Bear Weight of Gummy Bear (A-B) *Record this Value in Table 5

Table 5: Density Gummy Bear Data

 Day Start Time Stop Time Bear Color Head to Toe Length (cm) Arm to Arm Width (cm) Front to Back Thickness (cm) Volume (cm3) Mass (g) Density (g/ cm3) Day 1 n/a Day 2 n/a Difference (Day 1- Day 2) n/a n/a

Post-Lab Questions:

1. What was your hypothesis as to what would happen to the gummy bear? Was it correct?

2. How long did your gummy bear soak? What do you think would have happened if you left it in for twice as long?

3. Which change was greater, volume or mass? Explain your answer using scientific logic.

4. Which piece of information recorded in the data table do you think is least important? Explain why you think this is and why it had no effect on the results of the experiment.

5. How did the changes in mass and volume from Day 1 to Day 2 affect the density of your bear?

6. How could you get more accurate results from this lab? List and explain one way you could reduce your errors.

7. Using the sheet of graph paper in your kit, create a bar graph using the data in Table 5 to compare the density obtained for each day studied. You can also use a graphing program to create this graph. Hint: In order to scale the graph, you take the range of the numbers (the highest number and the lowest number), subtract them and divide by the number of lines on your graph. This will tell you how to divide up your graph evenly so it’s not all squished onto one area of the graph. Hint: The dependent variable is placed on the Y axis when the independent variable is placed on the X axis. When you create your graph, remember that the X and Y axes need to be labeled and you should give a title to your graph. Insert a picture of your graph.

8. Insert a final picture of your experiment with your name and access code handwritten in the background. 