Search found 315 matches

by bigmack
27 Aug 2019, 13:55
Forum: Biology, Physics...
Topic: Phenolphthalein Agar
Replies: 141
Views: 14382

Re: Phenolphthalein Agar

People have been wondering how long the phenolphthalein agar lasts for - I had some in the fridge when I started at this school in 2016 and didn't have to make more until this year. It worked perfectly and the only reason I had to make more was because it went mouldy. That's funny Marama , I just d...
by bigmack
27 Aug 2019, 10:35
Forum: Announcements
Topic: Will you be the lucky winner of the Golden Ticket?
Replies: 21
Views: 1010

Re: Will you be the lucky winner of the Golden Ticket?

J wrote:
26 Aug 2019, 09:32
No ticket here yet.
Mails a bit slow up the mountain J

I got a Blue one :D
ticket.jpg
by bigmack
12 Aug 2019, 14:55
Forum: Safety with Chemicals
Topic: Disposal of Sodium Thiosulfate?
Replies: 14
Views: 1543

Re: Sodium thiosulfate

sodium thiosulfate* sodium hyposulfite hypo 7-12 1 2 3 4 5 6 - NR Not Hazardous - - 7772-98-7 Moderately toxic if ingested. Forms toxic gases on contact with acids and on heating. Photographic fixer. Used in crystallisation experiments and redox titrations. Small quantities can be sued for chemical...
by bigmack
06 Aug 2019, 14:29
Forum: Recipes and Pracs
Topic: Iron II Sulfate
Replies: 14
Views: 1569

Re: Iron II Sulfate

Labbie wrote:
06 Aug 2019, 14:01
Put a Fe nail (NEW) of course into the solution, this helps it not going to Iron III a little slower. The little nail really does work.
Might give that a go Labbie
by bigmack
06 Aug 2019, 12:58
Forum: Recipes and Pracs
Topic: Iron II Sulfate
Replies: 14
Views: 1569

Re: Iron II Sulfate

On making this up, it is of course a light green. An old post but I normally make this up with tap water as recommended in the Labbies manual for most solutions except Silver Nitrate . Although the solid is a light green colour , the solution always quickly turns brown during stirring . Well this t...
by bigmack
01 Aug 2019, 17:56
Forum: Sourcing Materials & Eq Repairs
Topic: Chemical quality
Replies: 5
Views: 357

Re: Chemical quality

Well in fairness to Silform , I have to say this is the first time I have found an issue like this .
I made up some Silform Ferrous Sulfate after this ( also LR ) and it was perfectly fine .

Incidentally , I passed the Zinc Sulfate 4 times through filter paper before it was clear enough .
by bigmack
31 Jul 2019, 13:00
Forum: Sourcing Materials & Eq Repairs
Topic: Chemical quality
Replies: 5
Views: 357

Chemical quality

Made up some Zinc Sulfate solution using Silform brand . The Chem was powdery with a pinkish hue . powder.jpg The solution after mixing looked discusting with foam on the top and was very cloudy with a huge flocculent staring to settle after a bout an hour I tried filtering it and there wasn't that ...
by bigmack
30 Jul 2019, 10:19
Forum: Safety with Chemicals
Topic: Updated CIS Package???
Replies: 5
Views: 474

Re: Updated CIS Package???

Little bits and pieces seem to be changing in the online version . But all the chemicals seem to remain as they are in the old 20yr old printed copy .

Word is that there won't be a printed copy available .
by bigmack
23 Jul 2019, 14:01
Forum: Chemistry and Labware - General
Topic: identifying acids
Replies: 3
Views: 880

Re: identifying acids

I know that some Pickle used for stainless steel contains Hydroflouric Acid which is a DET banned chemical .....but its a liquid . You gave a powder that is added to water to make a pickle solution . A quick google showed Citric acid and sodium bisulpfate being common .One is food grade , the other ...
by bigmack
05 Jul 2019, 09:31
Forum: Sourcing Materials & Eq Repairs
Topic: water bath
Replies: 9
Views: 1032

Re: water bath

Merilyn1 wrote:
05 Jul 2019, 07:40
Honestly, I think setting the timer on the VHS recorder was easier than operating that hot plate!
:cheesy: Funny stuff Merilyn ....needed a good laugh today
by bigmack
04 Jul 2019, 13:58
Forum: Chemistry and Labware - General
Topic: Glass rod puzzle
Replies: 12
Views: 1260

Re: Glass rod puzzle

Thanks for the responses .....interesting . It would seem that its common to do it both ways, each has a valid reason . I asked my Chem teacher what he does . He said he gets the juniors to use the rubber/plastic end in solution to save wear on the beakers but says the seniors use that end as a hand...
by bigmack
03 Jul 2019, 12:31
Forum: Chemistry and Labware - General
Topic: Glass rod puzzle
Replies: 12
Views: 1260

Re: Glass rod puzzle

Here's my Puzzling question about the strirring rod. At a recent PL day while stirring a solution with a glass stirring rod I mentioned how the noise of the Yr12 Chem class had almost driven me batty last week .......tinkle ,tinkle, tinkle...... :crazy: Then a couple of Labbies looked at me puzzled ...
by bigmack
03 Jul 2019, 12:22
Forum: Sourcing Materials & Eq Repairs
Topic: Spring Balances
Replies: 7
Views: 525

Re: Spring Balances

OK they arrived . Pretty happy with them . They were all "Zeroe'd" on arrival . I checked all the 1N ones with a 100gm mass and they all weighed 100gm except for one that was 0.5gm out .....I'm pretty happy with that . :grin: Haines Spring Balances.jpg Here's a side by side with the older type we ha...
by bigmack
03 Jul 2019, 09:24
Forum: Sourcing Materials & Eq Repairs
Topic: Dropper bottle teats
Replies: 30
Views: 2822

Re: Dropper bottle teats

I'm not sure if even these ones are still available, might need to get onto MTA who have bought Serrata to see if they can help us out. If we can use the black ones on a lot of solutions, it will keep us out of trouble for a few years. The old Serrata link now brings you to MTA ....seems like they ...
by bigmack
02 Jul 2019, 15:36
Forum: Safety with Chemicals
Topic: LEAD NITRATE
Replies: 18
Views: 1410

Re: LEAD NITRATE

I totally get that its wrong and out of date but, my question was how have DET schools been labelling their Lead nitrate in the last 21 years ?

How have DET Labbies interpreted the CSIS info on it and used it to label their Lead Nitrate solutions ?