Title Liquid Volume Measurement Lab Purpose To develop

Title: Liquid Volume Measurement Lab

Purpose: To develop skill in measuring with the graduated cylinder and use of the metric system. Background: Scientists use the metric system so we can compare results from experiments. We read the graduated cylinder numbers at the bottom of the meniscus. We estimate one decimal place past where we can actually read. When mixing the primary pigment colors (red, yellow, blue), red and yellow make orange, yellow and blue make green, red and blue make purple.

Hypothesis: If we measure carefully and follow instructions carefully, we should get the same volume in each test tube and water colors in rainbow order. Materials: • 1 test tube rack, 6 test tubes, 3 250 m. L beakers, 3 pipettes, ~200 m. L red water, blue water, and yellow water solution

Lab Safety: Goggles to protect eyes, closetoed shoes to protect feet, wear aprons to protect clothing. Your role: Scientist, supplier, recorder, overseer Presentation: Table and Graph and any other observations you record

• Our measured volumes were not exactly what our calculated volumes predicted. Some reasons for the discrepancy include the following: • We did not read and follow directions carefully. • We read the meniscus a little differently each time • Some of the liquid spilled • Some of the liquid could have remained in the graduated cylinder when we poured it out each time

• Some of the liquid may have remained in the test tubes when pouring as well • When we rinsed both the test tube and the graduated cylinder, some water may have remained in the bottom of each • The colors of the water were not exactly a rainbow as expected. The purple turned out too blue. This was because Mrs. Bray did not measure the dye in each colored water solution. The concentrations of pigment were different in each solution.

• Conclusion: • Our hypothesis was partially supported. Some of our test tubes had 11. 0 m. L of water in them but most did not. Our colors mostly followed rainbow order but our orange was a little too red and our purple was too red. Too improve this experiment, we could make sure we measure the amount of dye accurately so the concentrations of pigment are the same in each colored water solution. If we do this again, we would be sure to follow instructions more carefully, measure more carefully and pour more carefully so the test tubes and graduated cylinders are emptied completely.

• The science we saw happening dealt with color mixing. We saw red and yellow make orange; yellow and blue make green; and blue and red make purple.