How do strong and weak acids differ? Use lab tools on your computer to find out! Dip the paper or the probe into solution to measure the pH, or put in the electrodes to measure the conductivity. Then see how concentration and strength affect pH. Can a weak acid solution have the same pH as a strong acid solution?

How do strong and weak acids differ? Use lab tools on your computer to find out! Dip the paper or the probe into solution to measure the pH, or put in the electrodes to measure the conductivity. Then see how concentration and strength affect pH. Can a weak acid solution have the same pH as a strong acid solution?

The PhET project at the University of Colorado creates "fun, interactive, research-based simulations of physical phenomena." This particular one deals with Beer's Law. "The thicker the glass, the darker the brew, the less the light that passes through." Make colorful concentrated and dilute solutions and explore how much light they absorb and transmit using a virtual spectrophotometer! The simulation is also paired with a teachers' guide and related resources from PhET. The simulation is also available in multiple languages.

The PhET project at the University of Colorado creates "fun, interactive, research-based simulations of physical phenomena." This particular one deals with Beer's Law. "The thicker the glass, the darker the brew, the less the light that passes through." Make colorful concentrated and dilute solutions and explore how much light they absorb and transmit using a virtual spectrophotometer! The simulation is also paired with a teachers' guide and related resources from PhET. The simulation is also available in multiple languages.

2.1 Solubility and Miscibility
2.2 Concentration
2.3 Dilution, Standard Solution, and Ion Concentrations
2.4 Solubility Curves and Tables
2.5 Precipitate Reactions
2.6 Selective Precipitation
Unit 2 Exam

2.1 Solubility and Miscibility
2.2 Concentration
2.3 Dilution, Standard Solutions and Ion Concentration
2.4 Solubility Curves and Tables
2.5 Precipitate Reactions
2.6 Selective Precipitation

Watch your solution change color as you mix chemicals with water. Then check molarity with the concentration meter. What are all the ways you can change the concentration of your solution? Switch solutes to compare different chemicals and find out how concentrated you can go before you hit saturation!

Une série de simulations provenant de l’Université de Colorado à Boulder pour les 9e – 12e au sujet des sciences. Cette simulation démontre le processus du Laboratoire Loi de Beer-Lambert.

Le projet PhET à l'Université du Colorado crée des "simulations amusantes, interactives et basées sur la recherche des phénomènes physiques". Celle-ci en particulier aborde la loi de Beer. "Plus le verre est épais, plus la bière est foncée, moins la lumière passe à travers." Créez des solutions colorées concentrées et diluées et explorez la quantité de lumière qu'elles absorbent et transmettent à l'aide d'un spectrophotomètre virtuel ! La simulation est également accompagnée d'un guide pour les enseignants et de ressources connexes de PhET.

Student teams are challenged to evaluate the design of several liquid soaps to answer the question, “Which soap is the best?” Through two simple teacher class demonstrations and the activity investigation, students learn about surface tension and how it is measured, the properties of surfactants (soaps), and how surfactants change the surface properties of liquids. As they evaluate the engineering design of real-world products (different liquid dish washing soap brands), students see the range of design constraints such as cost, reliability, effectiveness and environmental impact. By investigating the critical micelle concentration of various soaps, students determine which requires less volume to be an effective cleaning agent, factors related to both the cost and environmental impact of the surfactant. By investigating the minimum surface tension of the soap, students determine which dissolves dirt and oil most effectively and thus cleans with the least effort. Students evaluate these competing criteria and make their own determination as to which of five liquid soaps make the “best” soap, giving their own evidence and scientific reasoning. They make the connection between gathered data and the real-world experience in using these liquid soaps.

Students learn about the properties of solutions—such as ion interactions, surface tension and viscosity—as they make their own soap and shampoo and then compare their properties. Working as if they are chemical engineers, they explore and compare how the two surfactants behave in tap water, as well as classroom-prepared acidic water, hard water and seawater using four tests: a “shake test” (assessing the amount of bubbles produced), a surface tension test, a viscosity test, and a pH test. Then they coalesce their findings into a recommendation for how to engineer the best soap versus shampoo. The activity may be shortened by using purchased liquid soap and shampoo from which students proceed to conduct the four tests. A lab worksheet and post-quiz are provided.

Une série de simulations provenant de l’Université de Colorado à Boulder pour les 9e – 12e au sujet des sciences. Cette simulation démontre le processus de solutions acido-basiques.

Comment les acides forts et faibles diffèrent-ils ? Utilisez des outils de laboratoire sur votre ordinateur pour le découvrir ! Plongez le papier ou la sonde dans la solution pour mesurer le pH, ou insérez les électrodes pour mesurer la conductivité. Ensuite, observez comment la concentration et la force influent sur le pH. Une solution d'acide faible peut-elle avoir le même pH qu'une solution d'acide fort ?