Adjusted of Prep of Solution 5-04_Lab_Open Inq

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NAME Michael, Liani, Farhan, Dabe DATE 2/27/24 CLASS 1st Period INQUIRY LAB – OPEN Preparation of Solutions Chocolate milk is an example of a solution, in which a solute (chocolate syrup) is dissolved in a solvent (milk). If you like a lot of chocolate syrup in your milk you prefer concentrated chocolate milk. If you prefer only a little bit of chocolate syrup in your milk you like dilute chocolate milk. How can we relate this idea to chemistry? We would not use terms like “dilute” and “concentrated” to describe chocolate milk. We’d probably say we like it chocolatey or not too chocolatey. But when we are dealing with matter that is really small we need to describe quantities differently. For example, the molarity, M , of a solution is the number of moles of solute in one liter of solution. To determine the molarity of a solution, the following equation can be used: 𝑀??𝑎?𝑖?𝑦 (𝑀) = ????? ?? ?????? ?𝑖???? ?? ?????𝑖?? (𝑉) In conjunction with the molecular weight of a solute, this equation is used to determine the number of grams of solute needed to prepare a given volume of a solution with a specific concentration. Focus on Science Practices SEP 2 Developing and Using Models SEP 3 Planning and Carrying Out Investigations SEP 4 Analyzing and Interpreting Data SEP 5 Using Mathematics and Computational Thinking Materials Per Group ● Copper(II) sulfate, CuSO 4 •5H 2 O ● Balance ● Beaker, 50 ml to 250-mL ● Beral-type pipets, 2 ● Funnel ● Marker, waterproof ● Paper towels ● Spatula ● Graduated cylinder, 100-mL, 2 ● Wash bottle filled with water ● Wax pencil or labeling tape ● Weighing dish Copyright © 2019 Flinn Scientific, Inc. All Rights Reserved. Flinn Scientific and its affiliates are not responsible for any modifications made by end users to the content posted in its original format.

NAME Michael, Liani, Farhan, Dabe DATE 2/27/24 CLASS 1st Period Safety Copper(II) sulfate is moderately toxic by ingestion and inhalation and is a skin and respiratory irritant. Wear chemical splash goggles, chemical-resistant gloves, and a chemical-resistant apron. Please review current Safety Data Sheets for additional safety, handling, and disposal information. Procedure 1. Prepare 100 mL of a 0.10 M solution of CuSO 4 using water as the solvent. First, calculate the number of grams of copper(II) sulfate pentahydrate, CuSO 4 •5H 2 O, required to prepare 100 mL of a 0.10 M solution. V = 100 mL = 0.1 L M = 0.10 M n = M*V = (0.10 M)(0.1 L) = 0.01 mol 0.01 mol * 159.62/1 mole = 1.60g CuSO4 = 63.55 + 32.07 + 4(16) = 159.62 g/mol CuSO4*5H2O = 159.62 + 90 = 249.62 g/mol % CuSO4 = 159.62/249.62 * 100 = 63.95% 1.60g/0.6395 = 2.5g CuSO4 2. Once your calculation has been approved by your instructor, weigh out the required amount of copper(II) sulfate on a balance in a clean, dry weighing dish. 3. Transfer the solid to a clean, dry beaker. Use a wash bottle filled with distilled or deionized water to rinse any remaining solid from the weighing dish into the beaker. Dissolve the solid in the beaker in a minimum amount of distilled or deionized water. 4. Transfer the solution to a 100-mL graduated cylinder using a funnel. Rinse the beaker with distilled or deionized water using a wash bottle. Pour the rinse water through the funnel and into the graduated cylinder so that every bit of solid copper(II) sulfate or solution is transferred to the graduated cylinder. Rinse the beaker, running the rinse water through the funnel several times to thoroughly rinse both the beaker and the funnel. Copyright © 2019 Flinn Scientific, Inc. All Rights Reserved. Flinn Scientific and its affiliates are not responsible for any modifications made by end users to the content posted in its original format.

NAME Michael, Liani, Farhan, Dabe DATE 2/27/24 CLASS 1st Period 5. Slowly continue adding distilled or deionized water to the graduated cylinder until the liquid level is almost to the 100-mL mark. Fill to the mark with a pipet or wash bottle drop-by-drop so that no water splashes up on the sides of the flask. 6. Fill until the bottom of the meniscus is exactly at the 100-mL mark. 7. Develop a procedure to make 100 mL of 0.1 M CuSO 4 , using the 5 M CuSO 4 stock solution. Record your detailed procedure as well as any materials to be used. First we need to find the volume of 5 M CuSO4. We do this by multiplying 0.1 M and 100 mL. Once we have the answer, 10 M/mL, we divide it by 5 M. That will then give us 2 mL. Now that we know what the volume is for 5 M CuSO4 we need to dilute it to get 0.1 M. To do that we pour 2 mL of the stock solution in a graduated cylinder and then we will add 98 mL of water, to get 100 mL, to the 2 mL solution to dilute it and get 0.1 M. Copyright © 2019 Flinn Scientific, Inc. All Rights Reserved. Flinn Scientific and its affiliates are not responsible for any modifications made by end users to the content posted in its original format.

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NAME Michael, Liani, Farhan, Dabe DATE 2/27/24 CLASS 1st Period Analyze and Interpret Data 1. SEP Develop and Use Models Draw a model of the dilute solution and a model of the concentrated solution. Comment on their similarities and differences. 2. SEP Develop and Use Models How does the scale of matter you are working with prevent you from drawing a model that is 100 percent reflective of the contents in the two solutions you prepared? I am using a certain volume and a certain amount of solute. Drawing the model without the accurate measurement I won’t be able to draw a model that is 100 percent reflective of the contents in the two solutions we prepared. 3. SEP Analyze and Interpret Data How can you tell that the 0.5 M solution you prepared is more concentrated than the dilute, 0.1 M solution you prepared? When we add the water, it has a darker color than the 0.1M solution, which shows it has a higher concentration. Copyright © 2019 Flinn Scientific, Inc. All Rights Reserved. Flinn Scientific and its affiliates are not responsible for any modifications made by end users to the content posted in its original format.

NAME Michael, Liani, Farhan, Dabe DATE 2/27/24 CLASS 1st Period 4. SEP Use Mathematics and Computational Thinking Do you think the masses of the two CuSO 4 solutions you prepared are the same or different? Explain. I believe they are the same because the water diluted both of them fully and unless it is oversaturated, there will not be any difference between the two solutions besides concentration. 5. SEP Develop and Use Models Why does 100 mL of a 0.1 M solution of NaCl require a different amount of solid than 100 mL of a 0.1 M solution of CuSO 4 ? The formula to find the grams of CuSO4 is 0.01 mol * 159.62/1 mole = 1.60g And the formula to find the grams of NaCL is 0.01 mol * 58.44/1 mole = 0.6g which is a difference of 1 gram, which means the answers are going to differ from each other. 6. SEP Planning and Carrying Out Investigations If you needed the CuSO 4 you used to prepare the solutions back to run a different experiment, how could you separate the water from the solid? We can use the process of evaporation on a hot plate/burner to evaporate all the water until it becomes a saturated solution and continue heating until there are only crystals remaining. Copyright © 2019 Flinn Scientific, Inc. All Rights Reserved. Flinn Scientific and its affiliates are not responsible for any modifications made by end users to the content posted in its original format.

NAME Michael, Liani, Farhan, Dabe DATE 2/27/24 CLASS 1st Period Copyright © 2019 Flinn Scientific, Inc. All Rights Reserved. Flinn Scientific and its affiliates are not responsible for any modifications made by end users to the content posted in its original format.

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