Australia's Science Forum

No, food colouring does not have alcohol in it. I checked the ingredients yesterday on the bottles I have in stock. Apparently everything was recalled and then put back on the shelves. Bit silly really and very inconvenient when you go to stock up for that important prac that the teacher wants first...

This explains why I couldn't find a single skerrick of food colouring in Woolies this past week. I rang Woolies this afternoon and spoke to the grocery manager telling him that they were creating havoc nationwide amongst lab techs in high schools and he informed me that the food colouring and essenc...

No-one has mentioned a specific type of bunsen to be used for glasswork. I have several old style bunsens called "batwing bunsens" which give a very low hot blue flame for heating glass. They do not have a collar to regulate air intake. The top has a 2cm metal grid with fine holes. These b...

Ian, A single plastic coated winchester carrier will cost about $20 or so. I occasionally use mine to assist in pouring acids into beakers. The wire is easier to grip than the bottle and I take extra care to make sure that the carrier does not slip on bench surface. Cost wise the 2.5lt bottles are c...

Hi Pamela,
Check the online Southern Biological catalogue for sterile agar plates and prices.
Lyn

I have always used conc acid for this demonstration. Half a 250ml beaker of sugar and pour the acid to cover the surface. I offer to do this demonstration because I have had teachers through who have not handled this strength of chemical. For example competent teachers with backgrounds in maths, hom...

Thanks for replying Sue. The agar catastrophe is all a bit of a mystery. I used a stirrer hotplate but it takes so long to boil anything in the two litre beakers (anywhere up to three quarters of an hour on high) and then it only seems to simmer. The agar didn't seem to go as clear so perhaps it was...

A Galvanometer works really well with lemons so it should work with citric acid solution. I just tell the teachers that the globes don't work with this prac (in fact have never worked with this prac) and provide them with the galvanometers instead.

Lyn.

My "you beaut never fail" recipe for phenolphthalein agar went seriously off the rails last week. I was left with four litres of agar the consistency of jam. It is in the fridge at the moment and I am wondering if anyone has had a similar problem. The only thing different this time was tha...

I have just tried it with my chemicals and got no precipitate when adding 0.1M silver nitrate to 0.1M potassium sulfate. Sounds like you may have to make up a minute quantity of 1M for a teacher demonstration. I'ts always possible that it worked previously because the lab. tech used a 1M solution tr...

I didn't have a clue about dishwashers either so really relied on what was said on this website. I too had wanted a two drawer dishwasher but when I finally looked at what was available I decided that it was not as functional as the regular dishwashers particularly if I wanted to wash measuring cyli...

The Science Dimensions Teachers Editions also have the same sort of information which is on CD-ROM's. Each level has its own CD-ROM of information. There are risk assessment sheets for the student activities, risk assessment sheets for the lab technician, recipes for making up solutions of chemicals...

I have a new science teacher who has given me a fabulous recipe for slime. MATERIALS : 100ml beaker, Clag clear gum, Glycerine, Hand cream (Sorbolene), food colouring, stirring rod and Super-Saturated Borax solution . METHOD : In a 100ml beaker, ADD : 25ml clag clear gum; 2 or 3 drops of glycerine; ...

Hi Sharls, Just check the Southern Biological online catalogue. They have a revised edition and it's about $64-$65. Worth badgering your head of department to get one in. Downside is that you might have to keep it under lock and key so that the science teachers won't spirit it away. It does have rea...

Some people will do anything to be one of the faceless majority.

I have used the recipe which is in "The Laboratory" manual by B.Dungey which every lab technician should have at their fingertips. However I use 20g of agar per litre of distilled water to make a firmer usable agar. 20g agar 4g sodium hydroxide (solid) 1 litre distilled water Dissolve sodi...

Ah well! Here's another posting to keep you laughing. Had two new dishwashers installed in the past two weeks. One on each campus. Followed all the tips for sparkling glassware (thank you Richard and all the others out there). One machine buzzed a bit too loud for my liking and got a tad hot which w...

Hi out there to all those with experience in the use of dishwashers. I have finally scored an Electrolux dishwasher. It sat in my prep room and looked at me for three weeks before they finally chased down a plumber to install it. I need some advice as to how glassware should be stacked in the basket...

The topic of litmus paper was covered to some extent back in Sept 2007. Just type litmus paper into the search section and check out the suggestions.
Lyn.

Was the iodine a freshly made batch? If so what was your recipe? Did you have it stored in the small plastic dropper bottles?
Lyn.