Australia's Science Forum

Question: would you put cooking utensils through the dishwasher that has been used to clean beakers, testtubes, disection equipment etc? Not if I intended to ever cook with them again. Sure, in theory the idea of the dishwasher is that it thoroughly cleans the wares of all contaminants. But in prac...

Let's work with Summer..... Summer 'starts' Dec-1. The solstice is Dec-21. Officially this is the start of summer (that's what my Northern Hemisphere wife says - and I've never been able to convince her she is wrong about anything). If the solstice is the start of summer, then why was 'midsummer' a...

I don’t have any non-slip matting here but I assume they mean the sort of stuff people have by their sinks. Where does this come from? You want a large black rubber mat, preferably with holes to let the water wash through. Look for "Kitchen Mats" or "Shower Mats" at a har...

I accidentally found that using them as stainless steel electrodes in galvanic cells cleans them as well. I just can't remember what the solutions or the other electrodes were to reproduce it! It was a few years back and the teacher had forgotten to request the REAL stainless steel electrodes so sh...

Hydrochloric acid is a good rust solvent. It will also handle most residues. Just don't leave the spatulas overlong in an acid bath as it will also dissolve the iron! (And the chrome for that matter.) The problem is, they're rusty because the the chromium content of the steel surface has already bee...

Concentrated sulfuric acid should not decompose over time, unless it has been contaminated. Going brown is a likely sign that it is oxidizing something; check the glass or stopper.

What's the M&M half life prac? Sounds interesting :D Take a cup of radioactive M&Mium. Pour onto a sheet of paper/cloth. Sort and count the ones that land with M's face up (call them 'radioactive') and the ones which land with blank side face up ('safe'). Put the 'radioactive' M&Ms back...

We mix the Manganese dioxide with Plaster of Paris, and cut into small pellets when set. Use 3-4 pellets in a test tube with Hydrogen peroxide. No dust problems or black powder everywhere! 8-) Oh, I do like that. It is a rather good idea, Alice. I might try it out for next time. What ratio of manga...

Hi Fellow Chemtalkers, Just a question, Hasn't Maganese Dioxide been up graded in Hazard class to causing cancer? Well, it was implicated as a reproductive toxin and suspected carcinogen; esp. if it contains crystaline silicate impurities. Handle responsibly. Not sure but here's what is said in Ris...

Heinemann Science 10 pg 208-209 --Using a Catalyst. * spatula * Manganese dioxide (MnO2 or substitute KMnO4) * 5% Hydrogen peroxide * glass measuring cylinder * test tube * aluminium foil (cap for test tube) * glowing slplint * matches * Place a 1/4 spatula of Manganese dioxide into a test tube. * M...

I would think as you heated peroxide it would give off it's extra O becoming warm water That's why I store my H2O2 in fridge It decomposes into water and oxygen gas at above 80°C ; or earlier in the presence of catalists: metals, acids, oxidisable organic materials, etc. Heating is rather contra...

We have only two class labs, and just one fume hood. It is shared by the prep. lab though.

I can't imagine how your having to do preparations inside the class lab would be convenient for anyone.

lada wrote:If I get asked for egg and cannot get to shops, gelatine wins everytime. Dont even tell the kids, they just think its the egg white.
Works well.

Tofu also makes an eggcelent substitute. It contains a fairly high amount of colagulated protien.

After having a look through the different MSDS's for different brands, some say hazardous and some say not, and some say goggles and gloves and some say you don't need to. They all have similar compositions though. In fact the Boral's MSDS for casting plaster says non hazardous but the Chemwatch ve...

You have measured 200 gm of Nutrient Agar and 186gm plain agar and mixed them together and then use 15gm/litre of the Agar mixture. That's how it reads to me. She's mixing in bulk, storing, and weighing out from that as needed. It's a good idea. Need 500mL of nutrient agar? Weigh 7.5 grams of the p...

F.Y.I. The most recent update: http://hsis.safeworkaustralia.gov.au/Home/Updated (At time of posting:) CHANGE TO HAZARDOUS SUBSTANCE ENTRY FOR FORMALDEHYDE – July 2012 Based on the NICNAS (National Industrial Chemicals Notification and Assessment Scheme) Priority Existing Chemical Assessment ...

lab-woman wrote:I was told by a teacher today that it was in my Job Description that I had to show all "new" teachers how all of the science equipment works.

Wait. .... The new teachers don't know this already?

Check to see if Nichrome wire is a viable substitute.

You could alway just edit your Favourites link to use the full address. Are you using a version of Internet Explorer? If so, then instead of left-clicking on the link to open it, right-click on it to popup a menu. Select the "Properties" menu item to bring up a dialog box. On this move to ...

We mostly buy ours these days, with the old still kept as backup when the local shops don't have any in stock.

Not the most (cost/water) effecient way I know, but well enough for our small school's needs.

Also: Ye Olde Thread.