Osmosis Grape Lab done - Lecture notes 3-9 PDF

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Grape Osmosis Learning Goal: 1. SWBAT simulate the movement of water in and out of a cell by observe movement of water in and out of a grape under different conditions, predict the best type of solution (hypotonic, hypertonic, isotonic) needed to hydrate a person and be able to justify your understanding of these learning goals. Background Information: Osmosis is the diffusion of water across a membrane. Like other molecules, water will move from an area of high concentration to an area of low concentration. The more solute there is in a solution, the lower the concentration of water in that solution. There is terminology to describe concentration differences between two solutions. A solution with higher solute concentration is hypertonic relative to one with lower solute concentration. Conversely, a solution with lower solute concentration is hypotonic relative to one with higher solute concentration. If two solutions have the same concentration they are isotonic. Water will move from a hypotonic to a hypertonic solution. In humans, water is important. Human blood cells are slightly saline. The salinity of blood has a magic number of 9 or by weight 9 grams of salt to every 1000 grams of water. This means that every 1,000 grams of fluid contains 9 grams of salt and 991 grams of water. Materials: 4 grapes, 4 small cups, grape juice, tap water, salt water, sugar water, paper towels, marking pen, balance scale Procedure: 1. Using the chart provided, predict if the grape’s mass will increase, decrease, or remain the same after 48 hours in the solutions provided. Explain your prediction. 2. Using one of the 4 cups provided, half fill one cup with the grape juice solution. the second cup with the salt solution, the third cup with water, and the fourth cup with sugar water. Label each cup according to the solution it contains. 3. Place a grape on the balance scale and record the mass of each grape. 4. Place one grape in each solution and record the initial mass of that grape next to that type of solution.in each cup and carefully record its mass in each cup carefully identifying the proper mass for each solution. 5. Place a covering on over each cup and tightly secure it. 6. Mark the cup with a group name. 5. Place the cups carefully in the area directed by your teacher. 6. After 48 hours, remove each grape from its jar and dry it gently with paper towel. Using the balance scale, find its mass again. Record your results. 7. Complete the lab below and submit in CANVAS for a Lab Grade

Vocabulary Directions: Using your knowledge of osmosis, write a definition for the terms listed below. Hypertonic solution –More solute less solvent in comparison to the hypotonic solution Hypotonic solution –More solvent less solute in comparison to the hypertonic solution Isotonic solution –Same amount of solvent and solute in compared to other isotonic solution Procedure: 1. Prediction: Use what you know and what you have learned about isotonic, hypertonic, and hypotonic solutions and predict (make a check mark) if the mass of the grape will increase, decrease, or remain the same in grape juice, salt water and tap water, sugar water in the chart below Prediction Chart Grape increase in Grape decrease in Grape remain the mass mass mass In grape juice x In salt water x In tap water x In sugar water 2. Explain: Write your reason for your predictions.

x

Grape Juice- I think the grape and grape juice are isotonic compared to each other. Salt Water- I think the water is hypertonic compared to the grape making it shrink. Tap Water- I think the water is hypertonic compared to the grape making the grape grow. Sugar Water- I think because there is sugar in a grape the sugar water and grape are isotonic compared to each other. 3. Data table: Mass the grape and record the initial mass of the grape in the chart below Measurable Data Solution Initial mass of grape Mass of grape after 48 hours Grape juice

5.6

6.2

Salt water

7.3

8.2

Tap water

7.2

7.5

Sugar water

6.1

7.2

4. Experiment: a. Half fill one each cup with grape juice, the second with salt water, the 3 rd with tap water and the 4th with sugar water aligning with the proper initial mass b. Securely cover each cup and place where teacher directs you to place it. Wait 48 hours.

c. Remove the grape from each cup one at a time, mass the grape after 48 hours and record your findings in the appropriate column 5. Analysis: Answer the questions below and submit answers along with the entire lab through CANVAS for grading. 1. Identify the solution(s) in which osmosis occurred. 2.

How did you determine whether osmosis occurred in each of the solutions?

3. Which solution(s) caused the grape to shrink? Explain why this happened. None of the grapes shrunk because all the grapes were hypertonic to the hypotonic solution around it. 4. Which solution(s) caused the grape to swell? Explain why this happened. All the solutions caused the grapes to swell for the fact that the grapes were all hypertonic compared to the hypotonic solution surrounding them. 5. Which solution(s) did the mass of the grape remain the same? Explain why this happened. None of the masses of grapes stayed the same for the fact that none of the solutions were isotonic to the grapes. 6. Did the mass of each grape change as you predicted? Why or why not? No, the only grapes mass that changed as I predicted was the tap water solution which made the grape swell. 7. If a salt solution is hypertonic to a cell, why is a 0.9% saline and 5% dextrose intravenous solution used to hydrate the person? Explain. (HINT: Blood is slightly saline) The intravenous solution is used to hydrate a person blood cells because blood cells have more percentage of saline than the 0.9 saline solution which makes the blood hypertonic to the interevinous solution. Grading Rubric. 1. Has all components of the lab complete including vocabulary, prediction and explanation, completed data table, 7 analysis questions. 20 points 2. Missing vocabulary minus 3 points 3. Missing data table minus 1 point 4. Missing prediction minus 2 point 5. Missing prediction explanation minus 2 points 6. Missing analysis question answers up to 12 points depending on question missed....