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Chemistry Forums for Students => Undergraduate General Chemistry Forum => Problem of the Week Archive => Topic started by: Borek on May 20, 2013, 02:03:14 PM

Title: Problem of the week - 20/05/2013
Post by: Borek 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.
Title: Re: Problem of the week - 20/05/2013
Post by: Schrödinger on May 23, 2013, 06:18:23 AM
Pbonyg ; Fcunrebpbonygvgr
Title: Re: Problem of the week - 20/05/2013
Post by: delta609 on May 26, 2013, 01:44:02 PM
I think it's Rhodocrosite (MnCO3), but the calculations don't add up. 

MnCO3 + 2HCl  :rarrow: 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. 
Title: Re: Problem of the week - 20/05/2013
Post by: Borek 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.
Title: Re: Problem of the week - 20/05/2013
Post by: DrCMS on May 26, 2013, 02:55:28 PM
Sphaerocobaltite?
Title: Re: Problem of the week - 20/05/2013
Post by: Borek on May 26, 2013, 03:58:33 PM
Sphaerocobaltite?

Yes. But Schrödinger was first :)
Title: Re: Problem of the week - 20/05/2013
Post by: DrCMS on May 27, 2013, 03:05:59 AM
Yes. But Schrödinger was first :)

Yes I see now with rot13