Australia's Science Forum

Wouldn't this prac be referring to the Napisan type bleaches? They are supposed to work best in warm water. There are liquid forms available.

I would like to add that the teachers should be doing a risk assessment for each prac they do. In my opinion it would be impossible to do a risk assessment for a prac without specific chemicals.

When you say classroom quantities what size do you mean? You can buy larger size specimen jars from most supply companies. You are not supposed to transfer chemicals into old food containers.

I use 70 mL polypropylene specimen jars from Serrata. Cat no. 1230002 $41.00 for 100 in the2015/16 Catalogue. A few other places sell them as well.

Hi Kathryn,
Usually barium sulphate is one of the precipitates in precipitation pracs. Are you looking at the products from the prac rather than the solutions needed? Maybe check with the teacher exactly what they are doing.

We actually use close to saturated. That's what one of our previous chem teachers advised. You may want to try a weaker solution if you don't like to use that with kids. We do it in stations to avoid any mixing of chemicals. Solids make the best flame, but we don't do that. I only put out a small am...

For teachers who prefer loops, I make loops using Nichrome Wire. I bought a gauge that fits into the metal inoculating loop handles we already have. It's cheaper to use Nichrome wire than to buy the loops already made, and the loop is more robust. To make the loop I usually wind the wire around a ke...

Hi, probably too late for c.labs' decision, but we have just purchased one of the Omegas as a second dishwasher. (We have a lot of dishes here during certain times). The unit is good. Haines sells a test tube rack with prongs that replaces the standard domestic dishwasher rack (it is quite expensive...

Hi. I'm new to posting here but I have been reading the posts for a while (I'm from Queensland). I store thermometers in the wooden thermometer rack from Serrata. The holes were a bit small in the last one we bought, so we drilled larger holes. If thermometers are needed for a prac, I usually put th...