Catalysts Demonstrations
Catalysts are substances that affect the speed of a chemical reaction without being consumed in the process. This category explores how catalysts work, why they are important in both natural and industrial settings, and how they connect to ideas about energy and reaction rates. Understanding catalysts helps explain efficiency in chemical and biological systems.
| Demonstration | Materials | Difficulty | Safety | Summary |
|---|---|---|---|---|
| Detecting Fake Blood with Luminol | ★★★ | ★★☆ | ★★☆ | A luminol solution (luminol + sodium hydroxide + hydrogen peroxide) can be used to reveal “fake” blood stains made from blood meal fertilizer. The demo compares a control surface to areas stained with a blood-meal slurry and documents the chemiluminescent glow in the dark. |
| Elephant's Toothpaste | ★★☆ | ★★☆ | ★★☆ | 30% hydrogen peroxide is added to a potassium iodide catalyst, detergent and food colouring, and oxygen bubbles rapidly produce a foam. |
| Genie in a Bottle | ★★☆ | ★★☆ | ★★★ | When manganese dioxide is added to concentrated hydrogen peroxide, it rapidly decomposes into water and oxygen gas. The escaping oxygen propels a mist of water out of the container, creating the dramatic effect of a “genie” emerging from the bottle. |
| Oscillating Clock Reaction | ★★★ | ★★☆ | ★★☆ | The Briggs-Rauscher reaction is a dramatic oscillating chemical reaction in which a solution alternates between amber and blue-black colors several times before settling into a final dark-blue state. The color changes are caused by the interplay of iodine species, hydrogen peroxide, malonic acid, starch, and a manganese catalyst. |
| Pineapple Enzymes and Geletin | ★☆☆ | ★☆☆ | ★☆☆ | Bromelain in fresh pineapple prevents jelly from setting by digesting the gelatine protein. |
| Sweet Cracker | ★☆☆ | ★☆☆ | ★☆☆ | The enzyme amylase in saliva breaks down starch into sugar. A cracker initially tastes bland, but the longer it is chewed, the sweeter it becomes as starch is converted to glucose. |
Materials
★☆☆ Easy to get from supermarket or hardware store
★★☆ Available in most school laboratories or specialist stores
★★★ Requires materials not commonly found in school laboratories
Difficulty
★☆☆ Can be easily done by most teenagers
★★☆ Available in most school laboratories or specialist stores
★★★ Requires a more experienced teacher
Safety
★☆☆ Minimal safety procedures required
★★☆ Some safety precautions required to perform safely
★★★ Only to be attempted with adequate safety procedures and trained staff