acids/bases

The Write Stuff: Using Paper Chromatography to Separate an Ink Mixture

In this Activity, students perform a variation on the standard paper chromatography separation of black ink. They compare the separation of black ink using four different solvents: water, rubbing alcohol, vinegar, and household ammonia, and then mixtures of the four. It introduces students to methods of selecting the best solvent for a separation and the effects of adding acid and base.

More Than Meets the Eye: Nonvisual Observations in Chemistry

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.

Flat As a Pancake? Exploring Rising in Baked Goods

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.

Cabbage Patch Chemistry

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.

Acid-Base Reactions with Carbon Dioxide

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.

Acid Raindrops Keep Fallin' in My Lake

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.

Anthocyanins: A Colorful Class of Compounds

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.

How Big Is the Balloon? Stoichiometry Using Baking Soda and Vinegar

In this Activity, students discover the concept of stoichiometry and limiting reactants in two ways: first by adding vinegar to a small quantity of baking soda until bubbles stop, and second by mixing a constant quantity of baking soda with increasing volumes of vinegar and collecting the carbon dioxide produced in balloons. This Activity could be used in an introduction to stoichiometry.

Spring Shock! Impact of Spring Snowmelt on Lakes and Streams

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.