December 07, 2022, 02:15:38 AM
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Topic: Identifying unknown chemical  (Read 1627 times)

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Offline HerrSwampy

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Identifying unknown chemical
« on: October 11, 2022, 12:46:53 PM »
Hello, in my psychical chemistry lab we had done crysocopy exercise and i need to indentify chemical based on thesee informations:

molar mass: 45,21088 g/mol
white powder, easily made tablets with just pressure
Easily dissolves in water

Thanks for an help

Offline Babcock_Hall

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Re: Identifying unknown chemical
« Reply #1 on: October 11, 2022, 02:06:55 PM »
What are your thoughts?

Offline HerrSwampy

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Re: Identifying unknown chemical
« Reply #2 on: October 11, 2022, 02:18:24 PM »
It could have been MgO, but i am not sure at all

Offline mjc123

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Re: Identifying unknown chemical
« Reply #3 on: October 11, 2022, 02:49:45 PM »
If it was psychical chemistry, you should just know.

Offline HerrSwampy

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Re: Identifying unknown chemical
« Reply #4 on: October 11, 2022, 02:54:04 PM »
Sadly it was cryoscopy, and they just gave us the chemical and told us to find its molar mass and try to think what chemical it is

Offline Borek

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Re: Identifying unknown chemical
« Reply #5 on: October 11, 2022, 03:28:47 PM »
It could have been MgO, but i am not sure at all

Would MgO easily dissolve in water?

molar mass: 45,21088 g/mol

If it is your experimental value, it opens many more options. What is the heaviest element that the compound can contain? It is a compound, how many elements minimum does it contain? If so - what are possible molar masses of these element? Which elements fit? It is soluble - does it limit the selection of compounds? And so on.

Plus: often you are given a list of compounds to choose from.
« Last Edit: October 12, 2022, 03:03:16 PM by Borek »
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Offline HerrSwampy

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Re: Identifying unknown chemical
« Reply #6 on: October 11, 2022, 03:30:29 PM »
We were not given a list and yeah it was a experimental value of molar mass, so it could slightly different, I basicly need some idea that is closest to it

Offline Borek

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Re: Identifying unknown chemical
« Reply #7 on: October 11, 2022, 04:45:30 PM »
Can't think of anything else than trial and error building on the ideas I listed - or finding on the web a database of compounds and searching it for compounds with similar molar mass.
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Offline Orcio_87

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Re: Identifying unknown chemical
« Reply #8 on: October 12, 2022, 09:46:45 AM »
MgO would give an alkaline solution and its molar mass (40 g) differs from yours (45 g). There are other compounds that fit better - LiCl, Li2S and NaF.

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