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### Topic: Problem of the week - 20/05/2013  (Read 23983 times)

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#### Borek

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##### Problem of the week - 20/05/2013
« on: May 20, 2013, 02:03:14 PM »
When a sample of a rose red, rare mineral is reacted with 115.8 mL of 0.1 molar HCl, number of mLs of produced carbon dioxide (measured at 0°C and 1 atm) is identical to the molar mass of produced chloride. Identify the metal, name the mineral.
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#### Schrödinger

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##### Re: Problem of the week - 20/05/2013
« Reply #1 on: May 23, 2013, 06:18:23 AM »
Pbonyg ; Fcunrebpbonygvgr
"Destiny is not a matter of chance; but a matter of choice. It is not a thing to be waited for; it is a thing to be achieved."
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#### delta609

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##### Re: Problem of the week - 20/05/2013
« Reply #2 on: May 26, 2013, 01:44:02 PM »
I think it's Rhodocrosite (MnCO3), but the calculations don't add up.

MnCO3 + 2HCl  MnCl2 + CO2 + H2O

115.8 L of 0.1 molar HCl will produce .1289 mL CO2; whereas, the molar mass of MnCl2 is 125.9 g/mol.

#### Borek

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##### Re: Problem of the week - 20/05/2013
« Reply #3 on: May 26, 2013, 02:24:29 PM »
Calculations don't add up, because it is not the correct answer. But you are not that far.
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#### DrCMS

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##### Re: Problem of the week - 20/05/2013
« Reply #4 on: May 26, 2013, 02:55:28 PM »
Sphaerocobaltite?

#### Borek

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##### Re: Problem of the week - 20/05/2013
« Reply #5 on: May 26, 2013, 03:58:33 PM »
Sphaerocobaltite?

Yes. But Schrödinger was first
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#### DrCMS

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##### Re: Problem of the week - 20/05/2013
« Reply #6 on: May 27, 2013, 03:05:59 AM »
Yes. But Schrödinger was first

Yes I see now with rot13