Use 1-3% diatase, which is free from reducing sugars,or 1% bacterial amylase. These chemicals are available from Southern Biological.
Experiments
Incubator alternatives:
Here are tips for growing cultures without an incubator or a warm place such as a hot water system. Use a 40w incandescent globe, still available from Kmart and Big W but not Bunnings. Place petri dishes side by side and cover them with black plastic (bin liner). To keep a check on the temperature,…
Hydrogen Pop Test -Dangers:
Although most people have not had a problem with the hydrogen “pop” test, some schools have, with several cases of test tubes exploding and injuring students. It seems to be either inferior glassware, or students doing the pop test too close to the Hydrogen gas source, or a combination of both. It is recommended that…
Hydrogen peroxide decomposition:
Question: Re experiment 36 in the STAWA Chemistry Laboratory Manual, Factors affecting the rate of decomposition of hydrogen peroxide, what it is in liver that is a catalyst for the decomposition? Answer: The enzyme which decomposes hydrogen peroxide in liver is catalase. The experiment works well.
Globes-memory aid:
Small globes come in 2V, 6V and 12V sizes. The filament colours of the ones we use are different and the 6V globes are bigger than the others, so I find it easy to tell the difference. I now have the following poem pinned up near the globes. GLOBES! Blue are 2 6 are fat…
Energy content of food: peanut substitutes:
To determine the energy content of food products, substitute the following for peanuts: Cheezels, Doritos, potato chips, Vegie Chips, marshmallows, Tiny Teddies, Twisties, corn chips or Burger Rings.
Electro-magnets:
Question: Has anyone a good design for electro-magnets that actually works? It seems the designs in the texts are rather weak and not very effective. Answer: In order to have sufficient current passing through the wire, the wire must be rated to carry at least 3 amps. Wire of this thickness can cause the electromagnet…
Vitamin C content of fruit:
Question: Does anyone have information on how to test the Vitamin C content of different fruits? Answer: We do a simple practical using 5 different juices: freshly squeezed orange juice, bottled 100 percent cordial, lemon juice and boiled orange juice as comparisons. You could also use grapefruit but note that if you were using, for…
Tea bag rocket:
Use tag-bag teabags, the ones with the string and tag. These are actually tissue cylinders. Carefully remove the staple and the string and empty the tea out. Open the cylinder, but do not open out the fold. Place open side down on a bench. Light the folded part at the top, and observe. You can…