Density Column Experiment PDF

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Density Column Jennifer Baker C683 Natural Science Lab Section I: Introduction and Literature Review A. From an early age I have always loved to cook. I am not sure when I learned that oil and water do not mix. Perhaps, the concept was learned while making brownies when I was younger. A good box brownie mix requires both oil and water to be added to the brownie mix. I have never really thought of the science behind why oil and water do not mix, until now. “Density is a measure of how much mass is contained in a given unit volume, density = mass divided by volume” (Spangler, Steve, n.d.). Density is a concept that we are exposed to daily but probably do not think much about. “Freshwater, for example, has a density of about one gram per cubic centimeter at room temperature. Any compound—liquid or solid—that has a higher density than water will sink whereas substances with a lower density than that will float” (Buddies, 2016). When we think about liquids and their density, we discover that every liquid has a different density. Since, the densities of liquids are different they will react to each other in a different way. Section II: Hypothesis B. I hypothesize that liquids with varying densities will float on top of each other if placed in a glass container based on their density and the order in which they are placed, from most dense to least dense. C. My hypothesis is based on my research of the varying densities of liquids and how they react to each other. Section III: Method D. The independent variables in this experiment are the densities of the liquids. Since the densities of the liquids used are constant and will not change. E. The dependent variable is the level/layer of the liquid in the cylinder. Based on the density of the liquid we will use those measurements to determine which order the liquids should go into the cylinder in order to create a rainbow/column effect.

F. The external confounding variable in this experiment is the rate at which the liquids are poured into the cylinder. If the liquids are poured to quickly the velocity of the liquid will cause them to mix and not separate properly. To reduce the velocity of the liquid I will pour each liquid over a bent spoon to slow the velocity rate of the liquid thus creating the columns. G. Materials and Tools  Paper and Pencil  Graduated Cylinder 250ml or higher  Calculator  Digital Scale  710 ml glass cylinder (vase)  Spoon or ladle small enough to fit inside of the cylinder  Ruler  (5) 266 ml clear plastic cups  Food Coloring of your choice (one color needed)  Honey  Corn Syrup  Dish Soap  Water  Vegetable Oil H. Procedures 1. Set the graduated cylinder on your digital scale and 0 (zero) it out. 2. Measure out 200ml of honey and weigh the honey in the graduated cylinder on the digital scale and record your volume (200ml) and weight on your paper with a pencil. Pour the honey into (1) clear plastic cup and set aside. 3. Measure out 200 ml of corn syrup and weigh the corn syrup in the graduated cylinder on the digital scale and record your volume (200ml) and weight on your paper with a pencil. Pour the corn syrup into (1) clear plastic cup and set aside. 4. Measure out 200ml of dish soap and weigh the dish soap in the graduated cylinder on the digital scale and record your volume (200ml) and weight on your paper with a pencil. Pour the dish soap into (1) clear plastic cup and set aside. 5. Measure out 200 ml of water and weigh the water in the graduated cylinder on the digital scale and record your volume (200ml) and weight on your paper with a pencil. Pour the water into (1) clear plastic cup, add 5 drops of food coloring and set aside.

6. Measure out 200 ml of vegetable oil and weigh the vegetable oil in the graduated cylinder on the digital scale and record your volume (200ml) and weight on your paper with a pencil. Pour into (1) clear plastic cup and set aside. 7. Calculate the densities of the liquids by dividing mass by the volume. Record the densities on the corresponding liquid on your paper. 8. Determine which liquids are most dense and write them in descending order to determine which order the liquids go in the cylinder. 9. Start the column by pouring the honey into the cylinder. Pour the liquids carefully into the center of the cylinder; making sure the honey does not touch the sides of the cylinder while pouring. 10. Allow each layer to settle before adding the next one. The key is to pour slowly, evenly and carefully to minimize the velocity of the liquids. 11. Using the ladle/spoon to slow the velocity of the liquid by holding the spoon close to the surface of the honey but not touching it. Pour the corn syrup into the spoon allowing it to run slowly over the sides of the spoon. 12. Repeat this process with each liquid allowing a few minutes for each liquid to settle before pouring the next until all liquids have been poured in the order they are listed in the materials section. 13. Measure the sections in height to determine the order in which they are stacked and record your findings. i.e. the honey is 5 cm from the bottom of the cylinder to the corn syrup, the corn syrup is 10 cm from the bottom of the cylinder and 5 cm from the honey, ect.

Section IV: Result I. After calculating the density of the liquids listed, I determined the order in which the liquids need to be poured into the glass. Without calculating the densities prior to the experiment, I would not have known what order to pour the liquid into the cylinder to make the column correctly. The result was a density column with separated liquids according to density. I also used a ruler, pencil, and paper to measure where the liquids fall in the cylinder and recorded my findings in the table below. J. Liquid/Material Honey Corn Syrup Dish Soap Water

Density (g/ml) 1.42 1.33 1.06 1.00

Vegetable Oil

0.92

Liquid/Material Honey Corn Syrup Dish Soap Water Vegetable Oil

Height from bottom of cylinder 3 cm 6 cm 9 cm 12 cm 15 cm

Section V: Conclusions K. Based on the results of the density column pictured above my hypothesis is confirmed. The liquids when poured into a container according to density from least dense to most dense they remained separate. I also measured the liquids from the bottom of the cylinder to the bottom of the corresponding liquid to confirm the hypothesis.

L. It is my opinion that using liquids with densities that are in close proximity to each other might create a mixture rather than a stacking effect. This would be compounded by the velocity at which the liquid enters the cylinder. In conclusion choosing liquids with densities that are farther apart and pouring slowly into a spoon is best for creating a density column. M. I used the information provided by Steve Spangler Science (Spangler, Steve, n.d.) to calculate and determine the density of each liquid. I then used the information provided by Scientific American (Buddies, 2016) to determine what order and procedure for putting the liquids into the cylinder. Section VI: Sources N. Spangler, Steve, S. P. (n.d.). Seven Layer Density Column. Steve Spangler Science. Retrieved September 2, 2020, from https://www.stevespanglerscience.com/lab/experiments/sevenlayer-density-column/ Buddies, S. (2016, May 26). Stacking Liquids. Scientific American. https://www.scientificamerican.com/article/stacking-liquids/...