Australia's Science Forum

When I did this prac recently, I made the Bromine water using this recipe: In order to make 50mL Bromine water, you will need: • Glass bottle with screw cap, label the bottle Br2(aq) • 1.1 g sodium bromide, NaBr • 10.7 mL 1 M HCl • 7.6 mL sodium hypochlorite (household laundr...

As do Science Supply Australia and Labtek.

I have 10 sets which are complete enough to use for the junior classes. I would like to buy spares but I don't think they're available, so in a couple of cases I've had to paint styrofoam balls of about the same size in the appropriate colour. They do the job well enough.

Carol

I am back in science this term after spending Term 3 in the office. :clap3: :thumbup: I am having trouble with printing out the mini MSDS's. There is a delay of at least 5 minutes before the screen comes back after pressing the PRINT button, but when I try to print the full MSDS the print screen com...

I would make 100mLs of 2% (ie add 67mLs of the 3% H₂O₂ to 33mLs Distilled water), then take 50mLs of the 2% H₂O₂ and add 50mLs Distilled water to make 100mLs of 1% and just do the progressive dilutions.

OK, thanks.

I have some Power Supplies ST907A from Serrata which have blown fuses. I can't read the rating on the old fuses to buy replacements, but the instructions say "Max output 5.5A continuous with overload protection". Does this mean I need 5A fuses? And I'm assuming I want Quick Acting not Dela...

We've only got fluoro's too. But our chemical store is just a classroom that was divided into two storerooms. The shelving units are wooden frames with chipboard shelves. Over the past few years we've added a Flammable and a Corrosives cabinet, and had an exhaust system installed. The new cabinets a...

Hi, Ellice When I Googled this test I found : "Dissolve 50g of potassium chromate (K 2 Cr0 4 ) in 100mL of DI water and add silver nitrate (AgN0 3 ) until a slightly red precipitate is produced. Allow the solution to stand, protected from light, for at least 24 hours after the addition of AgN0 ...

I'm setting up the 'Titrimetric Determination of Chloride in Water' prac but I'm not sure what to use for the Potassium Chromate Indicator. Can I just use 0.1M K₂CrO₄ or does it have to have AgN0₃ added, rested and filtered out?

Carol

I have been having the same problem. Do a google search on 'polyester sailmakers thread'. I found a company called Raymond Traders PTY Ltd who look promising. They're in South Australia.

Carol

Well, I just opened Chemwatch and did a test search for THYMOL BLUE - need a password and username. So I did a search on ethanol - no problem. Then I tried thymol blue (lower case) - no problem ETHANOL (upper case) - no problem. Is this just a glitch on my computer??

Carol

Well, I restarted my computer - that didn't help. I went on to the DET Intranet looking for answers - found nothing. Retried the site three times - no good. Tried it again - now it's working.

I have just tried to use Chemwatch this morning and it is asking me for a username and password. It's never happened before. Has anyone else had this happen?

Carol

I googled and found this "Ringer solution - an aqueous solution containing the chlorides of sodium and potassium and calcium that is isotonic to animal tissues (ie has the same osmotic pressure as blood); used to correct dehydration and (in physiological experiments) as a medium for in vitro pr...

So is phosphorus still phosphorus or is it now fosforus??

This might help.

I had the same problem with some wood test tube racks I'd ordered from Livingstone. The top was paper thin and supported by four posts which were badly nailed together. They just collapsed sideways. I hadn't checked their catalogue, just re-ordered from previous invoice after checking the price with...

The boss here has told me on a couple of occasions that the school's insurance will cover me in the event of an accident occurring when I'm on school business. I think I should get that in writing.

We've been told that the cleaners are to supply rolls of paper towel to the staffrooms and toilets, but the science labs are our responsibility. When possible we filch some from the cleaners store, because they never leave any for our staffroom - they seem to expect us to look after ourselves. We ha...