Best M.W. information

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kimmy
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Best M.W. information

Post by kimmy »

OK i am doing up a new information booklet for the common chemicals i use at school. This is just for myself for making up solutions of my common chemcials.
So many sites have different information on them for the strength of chemicals.
What is the best site to get accurate information.
Even between the Working in Science book distributed to us from DET is different to the book "The Laboratory".

any suggestions will be appreciated.
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J
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Re: Best M.W. information

Post by J »

If in doubt, make your own calculations using the molecular weight of the chemical.
I have to rush off to a meeting now but I'm sure someone else can explain. Once you do this, you'll wonder why you ever had to look it up! :thumbup:
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kimmy
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Re: Best M.W. information

Post by kimmy »

J wrote: 20 Aug 2020, 10:10 If in doubt, make your own calculations using the molecular weight of the chemical.
I have to rush off to a meeting now but I'm sure someone else can explain. Once you do this, you'll wonder why you ever had to look it up! :thumbup:
Yes i know how to do this but even these are different on different sites. I just thought someone might know a site where it was the correct M.W.
eg Ammonium Oxalate
MW on Pub Chem is like 124.1
but on another site it is
142.11
Merilyn1
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Re: Best M.W. information

Post by Merilyn1 »

For molecular weight, check the individual container which will have it somewhere on the label, or, you can work it out from the formula, which will also be on the label. That would be the most reliable source.
bigmack
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Re: Best M.W. information

Post by bigmack »

Anhydrous versions have different MW.
That is why it is best to use the MW on the bottle .That way you know it matches what you have .Some recipe books don't state which type .
tin chloride.jpg
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shellythenewlabby
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Re: Best M.W. information

Post by shellythenewlabby »

Hi Kimmy
I usually use this website if i get stuck and have found it good. Hope it helps

https://www.sigmaaldrich.com/chemistry/ ... lator.html
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kimmy
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Re: Best M.W. information

Post by kimmy »

shellythenewlabby wrote: 20 Aug 2020, 11:45 Hi Kimmy
I usually use this website if i get stuck and have found it good. Hope it helps

https://www.sigmaaldrich.com/chemistry/ ... lator.html
thank you
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kimmy
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Re: Best M.W. information

Post by kimmy »

bigmack wrote: 20 Aug 2020, 11:38 Anhydrous versions have different MW.
That is why it is best to use the MW on the bottle .That way you know it matches what you have .Some recipe books don't state which type .

tin chloride.jpg
yes i think i will just go off my actual jars, thought there might have been a easier way.
Funny how it is hard to make our lives easy.
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Labbie
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Re: Best M.W. information

Post by Labbie »

Great information above, well done folks, hats off to you all.
Regards Labbie

Lab Manager/Lab Tech, mind reading etc etc
Now retired :wub:
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J
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Re: Best M.W. information

Post by J »

Merilyn1 wrote: 20 Aug 2020, 11:01 For molecular weight, check the individual container which will have it somewhere on the label, or, you can work it out from the formula, which will also be on the label. That would be the most reliable source.
Yes this is what I usually do.
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Re: Best M.W. information

Post by mtg »

I usually go off the container label, but I did download "Preparation of Solutions The Easy Reference" by S Rowley off chemtalk a while back. I use it to train new labbies or teachers. I also use The Laboratory but it has quite a few errors in it, if you can source "A Handbook of Laboratory Solutions. M.H.Gabb and W.E.Latchem", it is an excellent reference especially for stains and indicators.
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