In this Activity, students extract anthocyanins from flower petals and other plant matter. They observe what happens when vinegar or ammonia are added to the extracts. This Activity could be used as an introduction to the study of plant pigments and the idea that specific substances are responsible for the colors of objects.
Acids and Bases
In this Activity, students test the pH and acid neutralizing capacity of plain water, water that they blow their breath into, and water with either baking soda or lemon juice added. Students discover why normal rain is not neutral when they observe the effect of their breath on the pH of poorly buffered water.
In this Activity, students investigate "spring shock", the flow of acidic water into lakes and streams that occurs during snowmelt in the spring. They freeze vinegar in ice cube trays, and then allow the cubes to melt at room temperature through a funnel. They collect the liquid and monitor its pH. This Activity could be used in units on environmental chemistry and water chemistry.
In this Activity, students extract colored compounds from onion skins and blueberries, use them to dye white cloth, and investigate ways to change the color and prevent it from washing out. The Activity ties into the history of dyes. A study of the structures of dye molecules can be integrated into a discussion of organic chemistry and functional groups.
In this Activity, a blindfolded student, with another student as an assistant, observes the reaction between baking soda and cream of tartar in solution in a plastic bag. The Activity could be used at the start of a chemistry course to emphasize the importance of using all appropriate senses to make observations.
In this Activity, students investigate the action of leavening agents in baked goods. They first compare the results when leavening agents are added to water, with and without heating. They then prepare biscuits using dough that has been placed in different temperature environments and compare them. Preparing the biscuits requires an oven.
In this Activity, students investigate the fermentation process by making sauerkraut and test the effect of changing one variable in the sauerkraut-making process. The Activity involves students for an entire month, the length of the fermentation process.
In this Activity, students investigate two acid-base reactions. In the first reaction, an aqueous solution of powdered laundry detergent is neutralized with the acid formed by the dissolution of exhaled carbon dioxide. This uses the spice turmeric as an indicator. In the second reaction, vinegar and baking soda produce carbon dioxide gas.
In this Activity, students simulate acid rain falling on lakes by adding vinegar to bowls of water. Several of the bowls contain solids such as crushed, low-dust chalk, sand, and lime. Students determine whether the solids affect the acidity of each solution over two days by periodically removing samples of each solution for testing with red cabbage indicator.