FlinnPREP™ Inquiry Labs for AP® Chemistry: Properties of Buffer Solutions
By: The Flinn Staff
Item #: AP7663
In the Properties of Buffer Solutions Inquiry Lab Solution for AP® Chemistry, students attempt to design an ideal buffer solution effective in a specific pH range and to verify its buffer capacity.
Includes access to exclusive FlinnPREP™ digital content to combine the benefits of classroom, laboratory and digital learning. Each blended learning lab solution includes prelab videos about concepts, techniques and procedures, summary videos that relate the experiment to the AP® exam, built-in student lab safety training with assessments, and standards-based, tested inquiry labs with real sample data. FlinnPREP™ Inquiry Lab Solutions are adaptable to you and how you teach with multiple ways to access and run your AP® labs.
Big Idea 6, Investigation 16, Primary Learning Objective 6.18
What are buffers made of? How does a buffer work? Can a buffer be designed to be effective in a given pH range? Is there such a thing as an ideal buffer? The purpose of this advanced-inquiry lab kit is to design a buffer solution that will be effective in a specific pH range and to verify its buffer capacity.
Students begin the investigation with an introductory activity to explore the composition and pH of ideal buffers and compare their pH changes when a strong acid and base are added. Understanding the properties of buffers prepares students for the guided-inquiry challenge—to design a buffer that will provide effective protection at a specific pH and that will have the capacity to maintain the pH within a narrow range when prescribed amounts of acid and base are added.
Complete for 24 students working in pairs.
Materials Included in Kit: Acetic acid solution, 0.1 M, 500 mL, 2 Ammonium chloride, 10 g Ammonium hydroxide solution, 0.1 M, 500 mL Buffer envelope, pH 7 Citric acid solution, 0.1 M, 500 mL Hydrochloric acid solution, 0.5 M, 500 mL Seltzer water, 8 oz, bottle Sodium acetate, 30 g Sodium bicarbonate, 10 g Sodium dihydrogen citrate, 12 g Sodium hydroxide solution, 0.5 M, 500 mL Sodium phosphate solution, 0.1 M, 500 mL Sodium phospate, dibasic, 20 g
Additional Materials Required (for each lab group): Distilled water, 0.01-g precision balance (shared), beakers, buret or disposable pipets, graduated cylinders, pH meter or paper (indicators, optional), spatula, stirring rod, medium test tubes, test tube rack, wash bottle, weighing dishes.
Additional Materials Required (for Pre-Lab Preparation): Bottles to store solutions, Erlenmeyer flasks, graduated cylinders, magnetic stirrer and stir bar.
*Advanced Placement and AP are registered trademarks of the College Board, which was not involved in the production of, and does not endorse, these products.
Correlation to Next Generation Science Standards (NGSS)†
Science & Engineering Practices
Planning and carrying out investigations Analyzing and interpreting data Using mathematics and computational thinking Constructing explanations and designing solutions
Disciplinary Core Ideas
HS-PS1.A: Structure and Properties of Matter HS-PS1.B: Chemical Reactions
Patterns Cause and effect Scale, proportion, and quantity
HS-PS1-2. Construct and revise an explanation for the outcome of a simple chemical reaction based on the outermost electron states of atoms, trends in the periodic table, and knowledge of the patterns of chemical properties. HS-PS1-5. Apply scientific principles and evidence to provide an explanation about the effects of changing the temperature or concentration of the reacting particles on the rate at which a reaction occurs. HS-PS1-6. Refine the design of a chemical system by specifying a change in conditions that would produce increased amounts of products at equilibrium. HS-PS2-6. Communicate scientific and technical information about why the molecular-level structure is important in the functioning of designed materials.