Introduction: This demo shows a chemical reaction which can be used to show how concentration affects reaction rates. Students will observe and describe chemical and physical change. OBJECTIVE Differentiate between common chemical and physical changes. Analyse factors that influence chemical and physical change. INTENDED LEARNING OUTCOMES 1. Make observations and measurements 2. Collect and record…
Experiments
Indicators-making your own:
Re the experiment in Lower Secondary Science, Can you make an Indicator?: Red cabbage, red roses, onion skin and black tea work but flowers from your schools garden make great indicators. The following flowers work very well: Pink Camellia, flame tree, Grevillea Robyn Gordon, sour grass, nasturtium- orange flower form, white (with purple back) daisy,…
Ice cream, liquid nitrogen:
THIS EXPERIMENT MUST BE CARRIED OUT IN HYGIENIC CONDITIONS IN THE HOME ECONOMICS DEPARTMENT (APPLIED CONSUMER SCIENCE DEPARTMENT). USE FRESH INGREDIENTS FROM THE SUPERMARKET, NOT MATERIAL THAT HAS BEEN STORED IN CHEMICAL CUPBOARDS. USE APPROPRIATE PERSONAL PROTECTIVE EQUIPMENT WHEN USING LIQUID NITROGEN 1. You don’t need a strictly measured recipe but here’s a guideline: Pour…
Half-life:
Here is an experiment for demonstrating radioactive decay and half-life. 1.Get a packet of M&Ms (they only have an M on one side) 2.Count the M&Ms. 3.Place them in a beaker, shake and pour out onto a plate. 4.Remove the M&Ms that land face-up. These have decayed and need to be eaten immediately. 5.Count the…
Flame tests:
Question: Our text-book says to burn 2M solutions for flame tests, and I have tried solids too, but IT DOES NOT WORK! Can you please tell me what you do, and what actually works? Answer: Buy flame test bottles (atomisers) from Haines Educational. Use the following: All 0.5 M. Copper sulfate, sodium chloride, potassium chloride,…
Fingerprints-latent:
Question: Gentian Violet for fingerprinting is a banned substance now and is not procurable any more. Are there any alternatives? Answer: 1. On wood in silver nitrate. 2. Finger prints on filter paper in iodine chamber. Use a fume hood. Put fingerprints on filter paper and attach a paper clip and cotton thread to it,…
Fats and oils testing (emulsion test):
Add ethanol to a very small amount of the substance to be tested. Shake or crush to dissolve. In tough cases it can be warmed gently in a water bath. Filter or dilute if necessary to obtain a fairly clear liquid, which is the solution of fat in ethanol. Pour this solution into a test…
Esters experiment alternative:
Question: Can you please tell me the details of the experiment where you use jelly beans in lieu of esters? Answer: Esters – A Tasty Investigation (This activity compliments the Experiment 32 in STAWA Year 12 ATAR Exploring Chemistry Laboratory Manual). Key Ideas:Alcohols and carboxylic acids react to form esters. Esters have pleasant odours and…
Ecosystems:
Place yellow sticky traps from a hardware store in different areas of a garden. The following results came from one set-up: The trap near the non-native ornamental plants were full of white fly, the trap near the worm farm mainly had vinegar flies and the two fruit tree traps had lots of fruit flies because…
DNA Extraction:
Wheat germ, kiwi fruit and onion DNA extractions all work well. The wheat germ method is simple, you get lots of DNA, and it isn’t smelly. Test the detergent, as only some brands promote the production of DNA. EXTRACTION OF DNA FROM WHEAT GERM From Jan McGaw, Ferny Grove State High School, Queensland Raw wheat…