Day 1: After completing the pH Gizmo and preparing red cabbage indicator solution, students were formally introduced to acids and bases via a lab. Having just learned about indicators (chemical solutions that change color in response to changes in pH, Lesson 117) we reviewed Day 1 of the Acid and Base Lab Report Packet. and then students had the remainder of the day to work through the Day 1 worksheet and prepare for the lab.
Day 2: For Day 2 of the Acid and Base Lab, students used their red cabbage juice indicator solution to measure the pH of eight different solutions (comparing the color of the indicator to a color chart for red cabbage indicator). Students repeated the process using universal indicator. Finally, students evaluated the effect of sodium bicarbonate (baking soda) on the pH of the solutions, as determined by the indicator colors. Students should carefully document all steps of the lab, taking pictures of the indicator solutions before and after addition of sodium bicarbonate. Indicator Solution Charts are provided below:
Days 3+: Students will work with their assigned lab groups to write a lab report for the Acid and Base Lab. The lab report will consist of:
Introduction – a paragraph explaining the purpose of the lab
Safety Concerns – list all safety concerns associated with working with acids and bases, along with required precautions for the lab (explain why each piece of personal protective equipment is required)
Procedure – an ordered list of steps explaining:
how the red cabbage indicator solution was prepared
pH evaluation of all samples in universal indicator and red cabbage juice indicator solutions
pH evaluation of all samples after calcium carbonate added
pH measurement with pH probe
Results – data table with all results, pictures of all results, and one paragraph each of the outcomes of:
pH determined with red cabbage indicator solution
pH determined with universal indicator solution
pH determined with pH probe
pH determined after addition of calcium carbonate
Conclusions – one paragraph each explaining:
The effectiveness and consistency of indicator solutions, relative to the two indicator solutions compared with the pH probe
An explanation of how calcium carbonate affected pH
Bonus: An explanation of why the indicator solutions changed color (with sources cited)
Bonus: An explanation of why calcium carbonate affected pH (with sources cited)
Sources (if necessary)
Day 4: After a much-need 4-day weekend, we began class with the Lesson 84 PowerPoint which included a starter question helping students connect acid/base chemistry with the biology of heartburn. For the lab last week, students observed the effect of sodium bicarbonate (NaHCO3, or baking soda) on acids and bases. For the ChemCatalyst, students made the connection of acid neutralization with the related compound calcium carbonate (CaCO3, commonly found in antacids). Students have the remainder of the short week to complete the lab report from the lab last week. The group lab report packet is due at the end of school Friday, and the lab report must be shared with the teacher by midnight Friday. Late work will receive a maximum of 60% credit.
Groups who finished early will be provided with a variety of learning enrichment options related to our work thus far during the unit, including:
Evaluate absorbance and %transmission with a spectrophotometer, then create and analyze a graph
As we continue our study of pH, we need to explore techniques to determine whether a chemical is an acid, a base, or neutral. With yesterday’s Gizmo, students used digital pH paper to measure pH and then watched a video on how to prepare red cabbage indicator solution. Today we will prepare the red cabbage indicator solution that we will use in the lab tomorrow. In addition, students will read Lesson 117 in the textbook and answer exercise questions 1, 2, 3, and 6 in preparation for the Acid and Base Lab Report.
This week, we are extending our study of light and color to include the study of pH. We will begin with some class notes (below the video), and then students will have the remainder of the class period to complete the pH Analysis Gizmo and watch the video below showing how to prepare cabbage juice indicator solution. Be sure to write down the procedure for how to prepare the indicator solution – it will be going in your lab report!
For today’s work, students were assigned to read Lesson 115: Electromagnetic Radiation in the textbook, then answer the exercise questions at the end of the lesson. Answers to the questions will be turned in as an assignment.
For our work today, we reviewed exercise questions 3-6 from Lesson 113, took some class notes to set students up for success on Lessons 114 and 115. Students had the remainder of the class period to work on the exercises for Lesson 114.
After discussing the handout from Cosmos: Hiding in the Light, we transitioned to an exploration of the properties of light as a wave. Class notes are posted below. For the lesson, students were assigned to read Lesson 113: Light Energy in the textbook, then answer the exercise questions at the end of the lesson. Answers to the questions will be turned in as an assignment.
After completing another text analysis organizer, students compared and contrasted the two writing styles as part of a small group discussion. Next, we watched a video segment about the IPBES summary from Fox News. Students contrasted the articles with the video and evaluated the effect of tone on viewer perception of the material.
With so many possible sources of information out there, and the information often marketed as news but actually representing something other than objective fact, students watched The Baloney Detection kit video below. To help ensure everyone can differentiate between science and pseudoscience, students wrote down descriptions of all 10 points on a handout, with the expectation that they will use the points to determine whether a source should be used in our project work as students of science.
May 8: To begin class, we made use of some neat older equipment unearthed in our chemistry store room. Students used polarized light filters to visualize the emission spectra of hydrogen, helium, nitrogen, neon, argon, and mercury. We connected the emission spectra back to the concept of electron orbitals, previewing our work to come as the end of the year approached.
Next, we moved our “What Comes Next” discussion forward by creating a network diagram connecting facts from the CNN, NPR, and NBC News articles (key facts) with possible solutions (what can we do?). After building out the network diagram, students formed teams based on interest and were tasked with narrowing their own focus to the solution they would most like to explore and digging deeply into each solution by crafting a Project Proposal with the following elements:
Clearly describe the problem
Clearly describe the proposed solution and explain how you would use STEAM (science, technology, engineering, art, and math) to share your proposed solution with the class
Identify and explain the stakeholders: who or what will be impacted by the solution and why
Researchprevious efforts to solve the problem and identify what worked and what did not
Describe five major constraints: what are the realities of successfully implementing the solution? For example, cost is a universal constraint (everything costs money!) – how much might your solution cost (based on previous efforts) and who will pay?