Australia's Science Forum

Marama T wrote: ↑06 Feb 2024, 10:36 Zinc oxide changes colour at around 8000 degrees Celsius, so if you can get that organised I'd be most impressed.

Hahaha!! Sorry, I didn't google any further than that it changes colour

I just googled and found that zinc oxide changes to yellow when hot (white when cool).

Wondering how this prac request went and did you make methyl orange? It is good to make analytical reagents/indicators. I have a great book which has recipes for universal indicators, however I would google the chemical's safety, before purchasing. If necessary I would look for an alternative prac,...

Labbie wrote: ↑26 Jul 2023, 17:34 No just your Chemical's unopened. Not Dulited, solutions. No needed.

Is this stated anywhere in CSIS so that I can show the HT? Previously the chemical register at this school has included dilutions, but it's not very complete, so I as hoping to just eliminate that part if possible. Thanks

RosalieL wrote: ↑11 Sep 2023, 12:27

elaruu wrote: ↑07 Sep 2023, 09:15Yes, 4 litres

Thanks! I've just ordered one

Yay! I haven't yet. Still waiting for approval. Did you add on the free gift?

Yes, 4 litres

I think it's 4L. I was just assuming because it looks the same. But it doesn't seem to mention it on the website. I will double check before ordering. I think it would be much handier to have the big 10L tank, but oh well.

I had a 4L one at my previous school. I don't remember where I got it from but it worked really well and I don't remember changing the filters either! From memory, it did need a wipe out after each distillation as the base is where most of the gunk seemed to end up. I've just had a quick look onlin...

I used one of these at a school I worked at last year . Its an Air Still . You fill it up with about 2 liters of water , turn it on and it just sits there all day dribbling out distilled water . After 4-5 hours it auto switches off . No cooling water required . It consumes about 350 watts. So basic...

OK, have done a bit more research and I think it's the actual potassium permanganate that degrades over time. Does the acid accelerate this maybe? The non-acidified solution that we have is still nice and purple, but the dropper bottles labelled acidified are all clear with brown precipitate, so the...

Hi. Just wanting to ask another question about this. What happens to the acidified potassium permanganate over time that necessitates making it up fresh? Does it just neutralise, so go back to unacidified, or does something else happen? Just wondering if I had some bottles of "acidified potassi...

I read that about domestic pressure cookers too (on Science Assist). But then I googled the pressure of domestic pressure cookers and it said that they did reach this pressure. Who knows? I also looked briefly online for a laboratory pressure cooker and couldn't find one.

Thanks for that bigmack. I have used a microwave for melting agar (premade) in a previous life (research lab), and yes, you do have to be careful! The issue with the pressure cooker was not budget-related. This school generally spends money like nothing else! It was that the person in charge of sign...

I think I'd better not use the microwave, as the Science staff use it for food. (it's in my prep room but they heat their lunch in it). The pressure cooker purchase has been rejected, and I have been told to do it in bleach. I will do it in a big tub in an out of bounds area where it can be left ove...

Can I use a microwave (with the plates in an oven bag)? I read in another post that this is possible.

Always remember that pressure cookers are sold in shops where idiots can buy them . They have to be made idiot proof and safe or we would be hearing reports on the news of people being killed or badly burned by them . Depending on the size if them , you’ll be lucky to fit more than about 25 plates ...

Side note: The plates shouldn't be completely sealed by sticky tape. There should be a gap. If you're using parafilm, it goes all the way around. It's to do with tape creating an anaerobic environment and growing the wrong type of nasties. So are you saying being sealed with parafilm is ok because ...

Thanks Marama T. I didn't know that! I do hate to do it though. I do it in the fume hood but the smell still escapes. I have only actually done it twice here since I started a year and a half ago. It would be good to find an alternative. I will defo investigate getting a pressure cooker.

Thanks for the info bigmack. So you think the bleach would get in if submerged overnight even if not opened? I'll probably give that a go. And will also investigate the pressure cooker idea. They scare me a bit. I have never used one.

OK. Thanks. I was opening them up and soaking them in bleach inside a fume hood, so hopefully nothing spread. Much more preferable to wrap and throw away if that's acceptable.