acids/bases

Chemical Riddle #2

A student of mine, Anthony Shepherd, and I worked together to develop a new chemical riddle. Check out the video and see if you can come up with an answer.

Bath Bubblers

In this Activity, students use citric acid and baking soda to make "bath bubblers" similar to those sold in bath and body stores. They investigate the fizzing reaction that occurs when the bubblers are added to both cold and hot water. Bringing this real world product into the classroom adds interest and can lead to creativity, while introducing both acid/base concepts and rates of reaction.

pHantastic Fluorescence

In this Activity, students extract a fluorescent substance from shavings of narra wood. The pH-dependent fluorescence can be turned on and off using household acid and base solutions. A yellow filter blocks the exciting light but not the fluorescent emission. This Activity gets students thinking about the interaction of light and molecules.

A Kool Reaction from the Fine Print

In this Activity, students gain an understanding of the importance of reading reagent labels both in chemistry class and on consumer products. Students explore the chemistry behind the directive on a package of Kool-Aid "Do not store in a metal container". The Activity illustrates properties of acids and metals.

How Does Your Laundry Glow?

In this Activity, students examine the effect of pH on the intensity and color of the emission of fluorescent dyes in liquid laundry detergent. They perform two titrations using vinegar to estimate the pH at which the fluorescence properties change. In the second titration, sodium bicarbonate is added to buffer the detergent solution.

Soapmaking

In this Activity, students make soap using vegetable shortening as a base. They then test its properties and compare it to commercial soap. This Activity introduces students to an important reaction of organic chemistry. It helps students connect chemistry to something that they see and use every day and provides an opportunity for cross-curricular work.

Colors to Dye for: Preparation of Natural Dyes

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.

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.