Search found 405 matches

by mtg
12 Feb 2024, 15:14
Forum: Recipes and Pracs
Topic: making cell models
Replies: 10
Views: 3342

Re: making cell models

They shouldn't eat science experiments so use gelatine. Personally I hate the smell so I use jelly crystals, and whatever, split peas, pasta, no lollies etc. I have all different pasta shapes dyed different colours for one cell prac and they glue them onto a bit of card. I think bits of wool for wig...
by mtg
12 Feb 2024, 15:08
Forum: Announcements
Topic: Welcome back everyone
Replies: 18
Views: 1870

Re: Welcome back everyone

Welcome back to you all too. Invite all your labbie friends to get back onto chemtalk, I miss the daily discussions. It's a lonely job when you're the only school lab tech for miles.
by mtg
12 Feb 2024, 15:06
Forum: Recipes and Pracs
Topic: colour change when heated
Replies: 7
Views: 449

Re: colour change when heated

Keep me posted, I want to know if the iron oxide works.
by mtg
15 Nov 2023, 09:15
Forum: Safety with Chemicals
Topic: nickel sulfate
Replies: 11
Views: 4715

Re: nickel sulfate

I think the 0.1M is for precipitates. We use the foil for magnet pracs. Maybe the solid in crystal gardens. All waste is collected. PPE used. Dont touch it, drink it, or sniff it etc. Most of our chemicals will have associated dangers. You should always err on the side of caution and use PPE.
by mtg
08 Nov 2023, 08:07
Forum: Chemistry and Labware - General
Topic: McCartney Bottles
Replies: 2
Views: 741

Re: McCartney Bottles

Use a stopper. I have a stack of lids that seem to fit lots of little bottles. Don't know where they came from though. I use little bottles for powder testing, keep them in kits.
by mtg
18 Oct 2023, 11:39
Forum: Chemistry and Labware - General
Topic: Dresden ??? jar
Replies: 6
Views: 1090

Re: Dresden ??? jar

I would love to see a pic of the top and also of the rubber bung removed to have a better look at it but, I think the name is Dreschel Bottle It also seems to be called a Dressel bottle and a Drechsler bottle It is a Gas washing Jar as far as I can tell . Drechsler.jpg The inverted level marks I th...
by mtg
18 Oct 2023, 11:38
Forum: Chemistry and Labware - General
Topic: Dresden ??? jar
Replies: 6
Views: 1090

Re: Dresden ??? jar

Solution from an ex teacher. It is a transfusion bottle. From the old days when blood transfusions were done with glass bottles. The Bung top has 2 options for either metal or plastic insert. A small hole.
There is the long glass tube within to breathe so as to allow it to run when upside down.
by mtg
11 Oct 2023, 09:14
Forum: Chemistry and Labware - General
Topic: Dresden ??? jar
Replies: 6
Views: 1090

Re: Dresden ??? jar

pic:
jar.jpg
it has an outlet spot on top for a very small tube? And inside is a capillary tube like thing, so it must invert and displace something I think.
by mtg
11 Oct 2023, 08:54
Forum: Recipes and Pracs
Topic: Iodine Clock Reaction
Replies: 6
Views: 4374

Re: Iodine Clock Reaction

Wondering if anyone has an update for this reaction. my old recipe is 1. 0.10M Potassium Iodide (KI 16.60 g/L) 2. 0.01M Sodium Thiosulphate (Na2S2O3.5H2O, 2.48g/L) 3. 3% Starch 4. 0.04M Sodium Persulphate (Na2S2O8. 9.52g/L) mix 100ml of 1., 10ml of 2., and 1ml of 3.,in a 500ml flask. Add 100ml of 4....
by mtg
11 Oct 2023, 08:43
Forum: Forum Support Desk
Topic: How to post a picture on Chemtalk
Replies: 8
Views: 6924

Re: How to post a picture on Chemtalk

If you are posting Pics from an Iphone , you will still need to resize pics first .( I'm sure there would be an android version too) I have a free app called "resize It " .It is also handy for rotating pics that appear sideways when you post them . The trick for sideways pic is to click o...
by mtg
05 Oct 2023, 09:27
Forum: Chemistry and Labware - General
Topic: Dresden ??? jar
Replies: 6
Views: 1090

Dresden ??? jar

Help, how do I post a photo of glassware I am trying to identify? I thought it was a dresden jar but I can't find it when I search www, under that name.
by mtg
04 Oct 2023, 10:08
Forum: Chemistry and Labware - General
Topic: Chemicals not sold by Westlab or other common suppliers
Replies: 13
Views: 2506

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 mtg
03 Oct 2023, 12:47
Forum: Recipes and Pracs
Topic: barium nitrate solution.
Replies: 6
Views: 1881

Re: barium nitrate solution.

Depends how much you use, how much space you have etc. I sometimes decant into a bottle of each strength if they are in dropping bottles. I would keep 0.1M for sure.
by mtg
03 Oct 2023, 12:00
Forum: Chemistry and Labware - General
Topic: Burettes
Replies: 12
Views: 4173

Re: Burettes

I run it under warm to hot water, if you just want to tip it out/collection waste, diluting it wont matter.
by mtg
06 Sep 2023, 16:14
Forum: Safety with Chemicals
Topic: empty bottle disposal
Replies: 3
Views: 1369

Re: empty bottle disposal

Agreed Marama T, I reuse them if possible. But if they are clean should be recyclable.
by mtg
31 Aug 2023, 11:41
Forum: Recipes and Pracs
Topic: Silica gel for chemical garden
Replies: 7
Views: 2042

Re: Silica gel for chemical garden

I have sodium silicate solution, it is thick and doesn't work as well as the old solution I inherited. The original was made from a powder which you added water to and dissolved under pressure. firstly I never managed to dissolve it even with a pressure cooker. Secondly the newer one i bought is too...
by mtg
23 Aug 2023, 16:00
Forum: Sourcing Materials & Eq Repairs
Topic: refraction semi circles
Replies: 5
Views: 1137

Re: refraction semi circles

I always wondered what these were used for. Now I know. We have used beakers with different solutions.....despite having a few of the semi circle things. Another thing I know now. Thank you.
by mtg
23 Aug 2023, 15:57
Forum: Sourcing Materials & Eq Repairs
Topic: pinecone substitute
Replies: 6
Views: 1185

Re: pinecone substitute

I usually go and scavenge under pine trees, I haven't done this prac but it sounds cool so I will scavenge tonight and hopefully try it out.
by mtg
23 Aug 2023, 15:50
Forum: Safety with Chemicals
Topic: Gas syringe explosion
Replies: 7
Views: 1331

Re: Gas syringe explosion

Marama T wrote: 14 Aug 2023, 12:20 Totally. It was insane. Upside - no one got badly hurt and the kids love a good explosion. Downside - we were all shocked and went home thanking the gods of science for their mercy.
Yep we all love an explosion. But we will give this one a miss. :D
by mtg
20 Jul 2023, 16:16
Forum: Chemistry and Labware - General
Topic: A suitable demo?
Replies: 10
Views: 1739

Re: A suitable demo?

It's a bit like Dragons breath. Crazy physics teacher tried it but sprayed it thru a fire stick (broom handle with a lit taper attached) caught broom handle on fire, droplets onto the floor, also on fire. I decided it would not be a good demo. This idea is better.