Salt and citric acid- saturation investigations

1. Salt and citric acid- saturation investigations Rebecca McPherson

2. Learning Targets: EALR GLE • 2. Inquiry: The student knows and applies the skills, processes, and nature of scientific inquiry. • 2.1.2 Understand how to plan and conduct simple investigations following all safety rules.

3. Objectives: Students will be able to: • Make predictions of the results of an investigation. • Generate a logical plan for, and conduct, a simple controlled investigation with the following attributes: • Prediction • Appropriate materials and tools • Variables kept the same (controlled) • One changed variable (manipulated) • Measured (responding) variable • Gather, record, and organize data using units, charts, and/or graphs • Multiple trials • Identify and use simple equipment and tools (such as funnels, syringes, and balances). • Follow all safety rules during investigations (reviewed before every investigation).

4. Lesson Activities (Day 1): • Students conducted a simple salt saturation investigation. • Multiple trials were conducted and data was entered into a Smart Board chart. Students compared results. • Students were given a scientific illustration worksheet with two bottles drawn on it. They were to draw a visual representation of the difference between a salt solution and a saturated salt solution, adding labels as necessary.

5. Strengths and Problems: • Strengths: • Students were exposed to scientific vocabulary for the mixtures and solutions unit. • Students gained a clear understanding of the difference between a simple solution and a saturated solution through inquiry-based learning. • Weaknesses: • A formal procedure was not established. In future investigations I created my own lab report format, emphasizing essential learning requirements. • There was some confusion over where to record data. As a result, I created a chart to streamline the process.

6. Lesson Activities (Day 2): Students complete a citric acid investigation. • Investigative Question: How does changing the substance from salt to citric acid affect the mass of solute that dissolves to form a saturated solution. • Students will make a prediction. • Students will complete procedure. • Students will gather, organize, and record data using charts. • Students will identify one variable that was kept the same (controlled). • Students will identify the variable that was changed (manipulated). • Students will identify the measured (responding) variable. • Students will write a conclusion for the investigation.

7. Strengths and Weaknesses: • Strengths: • Students learned how to make scientific predictions. • Students learned the importance of following procedures. • Students learned how to write a scientific conclusion. • Students learned the importance of collecting data from a lot of trials. • Weaknesses: • The data chart provided my the district wasn’t user-friendly. In future investigations I created my own data charts. • The curriculum web’s explanation about how to write a scientific conclusion wasn’t thorough. As a result, some students were confused about what it entailed. I wrote a kid-friendly outline about what a formal lab report should include and how to format each section. In future investigations students were able to use this as a “how-to” guide.

8. Lesson Activities (Day 3): • Students designed their own investigation. • They asked the question, “How does the temperature of water affect the mass of citric acid that dissolves to form a saturated solution?” • Students wrote a plan for an investigation that could answer the students’ new question. It included: • Prediction (hypothesis) of the investigation results. • Materials needed to do the investigation. • Procedure that includes: • Logical steps to do the investigation • One variable kept the same • Only one variable changed • The measured variable • How often measurements are taken and recorded

9. Strengths and Weaknesses: • Strengths: • Students were able to practice writing a formal lab report. • Students became more comfortable writing predictions, procedures, and conclusions. • Weaknesses: • The space provided for a labeled diagram didn’t provide specific details about what it should include. In future investigations I provided students with written directions about what their diagram should entail.

10. Lesson Activities (Day 4): • Students completed a formal lab report, which included: • An investigative question • Prediction • Materials list • Procedure • Conclusion

11. Strengths and Weaknesses: • Strengths: • I created the formal lab report outline myself so it emphasized what I believe are the essential learning requirements in a kid-friendly format. • Students felt more confident writing predictions, procedures, and conclusions based on supporting data. • It serves as a “how-to” guide for future investigations.

12. “Sadie saturated 150 mL of water with sugar. Then she realized that she had lost track of how much sugar she had used. Explain what Sadie could do to find out how many grams of sugar she used to saturated the water.” Response from High-Achieving Student: Response from ELL Student: • To find out how many grams it took saturate the water she should set up a balance put her solution in one side put 150 mL of water in the other side and weigh until even with gram pieces. Amount in grams (gram pieces) is how much she put in. • Sadie can figure out how much sugar did she used by using the chart that shows the amount of sugar that can dissolve in the water. Sadie made the saturated solution with the sugar, so we can know how much sugar did she put by using the chart that shows the amount of sugar that can dissolve until it becomes to the saturated solution.

13. Joanne mixed two solid materials together, added water, and stirred. After a few minutes, the liquid was clear and there was a solid material on the bottom of the cup. Joanne used a paper filter to evaporate the solid from the liquid. Joanne thinks the clear liquid that passed through the filter is a solution. What should she do to find out? What would the results tell her? Response from High-Achieving Student: Response from “Average” Student: • She should evaporate it and if there are particles left she formed a solution. • Joanne should let the water evaporate and if something is left behind then it was a solution.

14. “Paco had a liquid he thought was a solution but not a mixture. Is it possible to have a solution but not a mixture?” “Average” Student: ELL Student: • No because all solutions are mixtures, but not all mixtures are solutions. • Yes. Because solution is a liquid that is made of two or more things and mixture is the thing that is made of two or more things that don’t combine.