In this problem students explore the concept of proportion by comparing the relative strengths of different mixes of juice flavor and water in a visual context. Given four mixtures represented by purple and white rectangles, students order the drinks from strongest to weakest flavor and explain their reasoning. The Teachers' Notes page offers suggestions for implementation, discussion questions, and ideas for extension and support.

What determines the concentration of a solution? Learn about the relationships between moles, liters, and molarity by adjusting the amount of solute and solution volume. Change solutes to compare different chemical compounds in water.

Explore what makes a reaction happen by colliding atoms and molecules. Design experiments with different reactions, concentrations, and temperatures. When are reactions reversible? What affects the rate of a reaction?

Explore what makes a reaction happen by colliding atoms and molecules. Design experiments with different reactions, concentrations, and temperatures. When are reactions reversible? What affects the rate of a reaction?

What happens when sugar and salt are added to water? Pour in sugar, shake in salt, and evaporate water to see the effects on concentration and conductivity. Zoom in to see how different sugar and salt compounds dissolve. Zoom in again to explore the role of water.

Before any instruction occurs on concentration, students use this activity and Tang to build on what they already know about concentration.
Using interactive models embedded in the google doc, students are able to drag and drop to build models of solutions with various concentrations.

Test the pH of things like coffee, spit, and soap to determine whether each is acidic, basic, or neutral. Visualize the relative number of hydroxide ions and hydronium ions in solution. Switch between logarithmic and linear scales. Investigate whether changing the volume or diluting with water affects the pH. Or you can design your own liquid!