# Lima Bean Lab

Lima Bean Lab

Making Accurate Measurements

Background: Over the next couple of class periods, you will practice your measuring skills. Your task is to make accurate measurements of seeds from the Phaseolus limensis plant, commonly known as the lima bean. You will measure the length, width, mass, and volume of the bean. This information will be recorded in a data table and you will calculate averages. Finally, you will soak the beans, take new measurements the second day and compare them to your first set of measurements.

Purpose: To accurately measure ten lima beans and calculate the percent of change after soaking in water.

Materials:

lima beanssmall cuptap waterbeaker

Day 1: Measuring Length, Width, Mass and Volume

You and your partner will work together to take measurements. Each person is responsible for turning in a complete lab report.

1. Copy the purpose onto your lab sheet.
2. Copy the materials onto your lab sheet.

Length and Width

1. Obtain 10 lima beans from your teacher. Each person is responsible for taking all of the measurements on 5 of the beans.
2. Number the beans 1-10 with a pencil (NOT pen). Make your numbers dark and easy to read.
3. Measure the length and width of the beans as precisely as you can, in millimeters (mm), using the metric ruler. Look at the diagram below to see where to take measurements on your beans. Fill in Data Table 1 with the measurements.

Width (center of bean)

Length

1. Calculate the average length and width of the beans in your sample. Fill in Data Table 1 with your averages.
2. Fill in the data chart on the board (for class data) with your averages.

Mass

1. Measure the mass of all your beans using the balance and record measurements in Data Table 2.
2. Calculate the average mass of the beans in your sample. Fill in Data Table 2 with your average.
3. Fill in the data chart on the board (for class data) with your average.

Volume

1. Measure exactly 50 mL of water using your graduated cylinder. Record this volume as your initial volume on Data Table 3.
2. Drop the 10 lima beans into the graduated cylinder and record the information as final volume.
3. Calculate the change in volume and record that number.
4. Calculate the average volume of one bean and record it.
5. Fill in the data chart on the board (for class data) with your average.

Storage and Soaking of the Beans

1. Write your group number (assigned by your teacher) on the small cup.
2. Measure out 50 mL of water with the graduated cylinder and pour it into the cup.
3. Drop all of the beans into the water in the cup and let them sit until the next class period.
4. Write a hypothesis describing how the beans will change after soaking.
5. Tell how much of a % change you think there will be.
6. Tell whether you think the beans will be larger, smaller, or no change.
7. Write your hypothesis in the hypothesis section just below the materials section.
8. Clean up your lab station. The lab will conclude the next class period.

Day 2: Observing Changes, Analysis and Conclusion

Re-measuring

1. Get your labeled cup with the soaking beans. Pour off any extra water.
2. VERY CAREFULLY pat your beans dry, trying to leave skins on the beans. If the skins came off while soaking, try to figure out which skin goes with which bean.
3. Re-measure the length and width of each bean and fill in Data Table 4 and the class data chart.
4. Re-measure the mass of each bean and fill in Data Table 5 and the class data chart.
5. Re-measure the volume of the beans and fill in Data Table 6 and the class data chart.

Data Analysis

1. Using all of your previous data tables, complete Data Table 7 by filling in the appropriate information.
2. Using the Calculations section, calculate the % of change for each bean (for length, width, mass, and volume) by using the following formula:

% of change = (final – initial / initial) X 100

Conclusion:

1. Answer the conclusion questions in the conclusion section.
2. Write a conclusion paragraph.
3. Discuss whether or not your hypothesis was correct and why or why not.
4. Discuss your analysis of the class data.
5. Conclude how soaking the beans in water affected them.

Name: ______

Period: ______

Lima Bean Lab

Making Accurate Measurements

Student Lab Sheet

Purpose:______

______

Materials:______

______

Hypothesis:______

______

Data:

Data Table 1: Length and Width (Day 1)Data Table 2: Mass (Day 1)

Length / Width
1
2
3
4
5
6
7
8
9
10
Average
Class Average
Mass
1
2
3
4
5
6
7
8
9
10
Average
Class Average

Data Table 3: Volume (Day 1)

Initial Volume / Final Volume / Change in Volume / Average / Class Average

Data Table 4: Length and Width (Day 2)Data Table 5: Mass (Day 2)

Length / Width
1
2
3
4
5
6
7
8
9
10
Average
Class Average
Mass
1
2
3
4
5
6
7
8
9
10
Average
Class Average

Data Table 6: Volume (Day 2)

Initial Volume / Final Volume / Change in Volume / Average / Class Average

Data Table 7: Analysis

Average Length / Average Width / Average Mass / Average Volume
Day 1
Day 2
% Change
Class Average
% Change

Questions: Answer on another sheet of paper and staple to lab.

1. What are some sources of error in this type of lab?
2. What other observable changes did you notice in your beans after you soaked them?
3. Why do you think the beans changed overnight like they did?
4. What do you think would happen to the beans of they were soaked for 3 more days?
5. When beans mature on the plant, they are dry. How might this be an advantage for the survival of the plant species?

Conclusion:______