Chemical quality

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bigmack
Posts: 360
Joined: 15 Dec 2015, 10:49
Job Title: Lab Assistant
State/Location: NSW

Chemical quality

Post by bigmack » 31 Jul 2019, 13:00

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 much improvement .
Silform.jpg
I opened a jar of Ajax Finechem .
The chemical looked more crystalline .
Crystals.jpg
The solution was clear as water
Ajax Finechem.jpg
So I wonder is this the difference between AR and LR grade or is it a brand issue .
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Labbie
Posts: 2881
Joined: 28 Nov 2006, 10:00
Job Title: Retired
Suburb: At Home
State/Location: NSW

Re: Chemical quality

Post by Labbie » 31 Jul 2019, 17:51

LR Laboratory Reagent
GR General Reagent
AR Analytical Reagent
Regards Labbie

Lab Manager/Lab Tech, mind reading etc etc
Now retired :wub:

Merilyn1
Posts: 885
Joined: 12 Mar 2013, 08:10
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School: Wollondilly Anglican College
Suburb: Tahmoor
State/Location: NSW

Re: Chemical quality

Post by Merilyn1 » 01 Aug 2019, 07:37

I only buy the LR grade, unless there is nothing else available. I would suspect it is the quality of the brand. I would send the photos to the supplier and question them about it. I've only known zinc sulfate to be a clear solution.
Oh, and often, I get crystals or powder for the same chemical. So I don't think that's the problem. Although that powder looks really gluggy.

MariaQ
Posts: 45
Joined: 02 Sep 2015, 08:41
Job Title: Boss
School: Central Coast Grammar
State/Location: NSW

Re: Chemical quality

Post by MariaQ » 01 Aug 2019, 09:23

I bought some chemicals from Silform, and found they were a lot lower grade, especially the magnesium ribbon, I probably wont buy from them again. MariaQ

karend
Posts: 49
Joined: 10 Aug 2012, 14:13
State/Location: NSW

Re: Chemical quality

Post by karend » 01 Aug 2019, 14:39

I won't purchase any chemicals from Silform, the quality is very, very poor

bigmack
Posts: 360
Joined: 15 Dec 2015, 10:49
Job Title: Lab Assistant
State/Location: NSW

Re: Chemical quality

Post by bigmack » 01 Aug 2019, 17:56

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 .

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