Search found 44 matches
- 21 May 2024, 13:05
- Forum: Sourcing Materials & Eq Repairs
- Topic: Hoffman voltameter
- Replies: 8
- Views: 149
Re: Hoffman voltameter
Thanks both. We'll probably get that one too if it's decided we need a new one.
- 21 May 2024, 09:23
- Forum: Sourcing Materials & Eq Repairs
- Topic: Hoffman voltameter
- Replies: 8
- Views: 149
Re: Hoffman voltameter
Does anyone have any feedback on the plastic one in the link above?
- 21 May 2024, 09:22
- Forum: Sourcing Materials & Eq Repairs
- Topic: Hoffman voltameter
- Replies: 8
- Views: 149
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.
- 20 May 2024, 14:37
- Forum: Sourcing Materials & Eq Repairs
- Topic: Hoffman voltameter
- Replies: 8
- Views: 149
Re: Hoffman voltameter
Thanks. The liquid is leaking out of the glass taps at the top. The bungs seem to be OK.
- 20 May 2024, 11:03
- Forum: Sourcing Materials & Eq Repairs
- Topic: Hoffman voltameter
- Replies: 8
- Views: 149
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...
- 06 Feb 2024, 12:26
- Forum: Recipes and Pracs
- Topic: colour change when heated
- Replies: 7
- Views: 2863
- 06 Feb 2024, 09:22
- Forum: Recipes and Pracs
- Topic: colour change when heated
- Replies: 7
- Views: 2863
Re: colour change when heated
I just googled and found that zinc oxide changes to yellow when hot (white when cool).
- 12 Oct 2023, 09:45
- Forum: Chemistry and Labware - General
- Topic: Chemicals not sold by Westlab or other common suppliers
- Replies: 13
- Views: 6849
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,...
- 13 Sep 2023, 13:01
- Forum: Chemistry and Labware - General
- Topic: chemical register
- Replies: 14
- Views: 9494
Re: chemical register
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
- 12 Sep 2023, 08:45
- Forum: Chemistry and Labware - General
- Topic: Water purifier - deioniser etc
- Replies: 35
- Views: 28135
- 07 Sep 2023, 09:15
- Forum: Chemistry and Labware - General
- Topic: Water purifier - deioniser etc
- Replies: 35
- Views: 28135
Re: Water purifier - deioniser etc
Yes, 4 litres
- 07 Sep 2023, 09:09
- Forum: Chemistry and Labware - General
- Topic: Water purifier - deioniser etc
- Replies: 35
- Views: 28135
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.
- 05 Sep 2023, 14:27
- Forum: Chemistry and Labware - General
- Topic: Water purifier - deioniser etc
- Replies: 35
- Views: 28135
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...
- 05 Sep 2023, 12:49
- Forum: Chemistry and Labware - General
- Topic: Water purifier - deioniser etc
- Replies: 35
- Views: 28135
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...
- 03 Aug 2023, 12:06
- Forum: Recipes and Pracs
- Topic: acidified potassium permanganate
- Replies: 14
- Views: 9064
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...
- 03 Aug 2023, 10:30
- Forum: Recipes and Pracs
- Topic: acidified potassium permanganate
- Replies: 14
- Views: 9064
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...
- 06 Jun 2023, 12:48
- Forum: Biology, Physics...
- Topic: Disposal of used agar plates
- Replies: 33
- Views: 18888
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.
- 06 Jun 2023, 08:51
- Forum: Biology, Physics...
- Topic: Disposal of used agar plates
- Replies: 33
- Views: 18888
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...
- 05 Jun 2023, 14:58
- Forum: Biology, Physics...
- Topic: Disposal of used agar plates
- Replies: 33
- Views: 18888
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...
- 05 Jun 2023, 10:28
- Forum: Biology, Physics...
- Topic: Disposal of used agar plates
- Replies: 33
- Views: 18888
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.