Search found 43 matches

by elaruu
21 May 2024, 09:23
Forum: Sourcing Materials & Eq Repairs
Topic: Hoffman voltameter
Replies: 5
Views: 73

Re: Hoffman voltameter

Does anyone have any feedback on the plastic one in the link above?
by elaruu
21 May 2024, 09:22
Forum: Sourcing Materials & Eq Repairs
Topic: Hoffman voltameter
Replies: 5
Views: 73

Re: Hoffman voltameter

Thanks bigmack. I will try silicon grease. The teacher specifically asked for sodium sulfate rather than sulfuric acid because she doesn't like the acid leaking everywhere.
by elaruu
20 May 2024, 14:37
Forum: Sourcing Materials & Eq Repairs
Topic: Hoffman voltameter
Replies: 5
Views: 73

Re: Hoffman voltameter

Thanks. The liquid is leaking out of the glass taps at the top. The bungs seem to be OK.
by elaruu
20 May 2024, 11:03
Forum: Sourcing Materials & Eq Repairs
Topic: Hoffman voltameter
Replies: 5
Views: 73

Hoffman voltameter

Hi, We are having trouble with our glass Hoffman voltameter leaking. It leaks the sodium sulfate solution from the taps at the top, but only slightly, and the gas escapes very quickly as the pressure builds up. Is there anything I can do to stop the leaking? It's like this one I think: https://www.t...
by elaruu
06 Feb 2024, 12:26
Forum: Recipes and Pracs
Topic: colour change when heated
Replies: 7
Views: 2716

Re: colour change when heated

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 :crazy:
by elaruu
06 Feb 2024, 09:22
Forum: Recipes and Pracs
Topic: colour change when heated
Replies: 7
Views: 2716

Re: colour change when heated

I just googled and found that zinc oxide changes to yellow when hot (white when cool).
by elaruu
12 Oct 2023, 09:45
Forum: Chemistry and Labware - General
Topic: Chemicals not sold by Westlab or other common suppliers
Replies: 13
Views: 6681

Re: Chemicals not sold by Westlab or other common suppliers

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,...
by elaruu
13 Sep 2023, 13:01
Forum: Chemistry and Labware - General
Topic: chemical register
Replies: 14
Views: 9243

Re: chemical register

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 :)
by elaruu
12 Sep 2023, 08:45
Forum: Chemistry and Labware - General
Topic: Water purifier - deioniser etc
Replies: 35
Views: 27815

Re: Water purifier - deioniser etc

RosalieL wrote: 11 Sep 2023, 12:27
elaruu wrote: 07 Sep 2023, 09:15Yes, 4 litres
Thanks! I've just ordered one :thumbup:
Yay! I haven't yet. Still waiting for approval. Did you add on the free gift? :D
by elaruu
07 Sep 2023, 09:15
Forum: Chemistry and Labware - General
Topic: Water purifier - deioniser etc
Replies: 35
Views: 27815

Re: Water purifier - deioniser etc

Yes, 4 litres
by elaruu
07 Sep 2023, 09:09
Forum: Chemistry and Labware - General
Topic: Water purifier - deioniser etc
Replies: 35
Views: 27815

Re: Water purifier - deioniser etc

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.
by elaruu
05 Sep 2023, 14:27
Forum: Chemistry and Labware - General
Topic: Water purifier - deioniser etc
Replies: 35
Views: 27815

Re: Water purifier - deioniser etc

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...
by elaruu
05 Sep 2023, 12:49
Forum: Chemistry and Labware - General
Topic: Water purifier - deioniser etc
Replies: 35
Views: 27815

Re: Water purifier - deioniser etc

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...
by elaruu
03 Aug 2023, 12:06
Forum: Recipes and Pracs
Topic: acidified potassium permanganate
Replies: 14
Views: 8932

Re: acidified potassium permanganate

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...
by elaruu
03 Aug 2023, 10:30
Forum: Recipes and Pracs
Topic: acidified potassium permanganate
Replies: 14
Views: 8932

Re: acidified potassium permanganate

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...
by elaruu
06 Jun 2023, 12:48
Forum: Biology, Physics...
Topic: Disposal of used agar plates
Replies: 33
Views: 18610

Re: Disposal of used agar plates

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.
by elaruu
06 Jun 2023, 08:51
Forum: Biology, Physics...
Topic: Disposal of used agar plates
Replies: 33
Views: 18610

Re: Disposal of used agar plates

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...
by elaruu
05 Jun 2023, 14:58
Forum: Biology, Physics...
Topic: Disposal of used agar plates
Replies: 33
Views: 18610

Re: Disposal of used agar plates

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...
by elaruu
05 Jun 2023, 10:28
Forum: Biology, Physics...
Topic: Disposal of used agar plates
Replies: 33
Views: 18610

Re: Disposal of used agar plates

Can I use a microwave (with the plates in an oven bag)? I read in another post that this is possible.
by elaruu
02 Jun 2023, 18:50
Forum: Biology, Physics...
Topic: Disposal of used agar plates
Replies: 33
Views: 18610

Re: Disposal of used agar plates

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 ...