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Saturday's - "Fun with Chemistry" problem:

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ChromeFoundry Donating Member (1000+ posts) Send PM | Profile | Ignore Sat Apr-30-11 10:26 PM
Original message
Saturday's - "Fun with Chemistry" problem:
Ok, so here is the problem for the evening:

Q: What mass of pure CaCO3 must be used to prepare 500 mL of an aqueous solution that has a concentration of 950 mg L-1 Ca2+ ion?


  • a) 0.190 g

  • b) 0.475 g

  • c) 0.594 g

  • d) 1.190 g
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bluesbassman Donating Member (1000+ posts) Send PM | Profile | Ignore Sat Apr-30-11 10:42 PM
Response to Original message
1. That's a trick question. The coin never left his hand!
:)
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petronius Donating Member (1000+ posts) Send PM | Profile | Ignore Sat Apr-30-11 10:46 PM
Response to Original message
2. C. The answer is always C...
(Except when it's D)
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struggle4progress Donating Member (1000+ posts) Send PM | Profile | Ignore Sun May-01-11 01:20 AM
Response to Original message
3. Wikipedia says MW is around 100g and solubility in room temp water is around 0.00015 mol/L
so at room temp you're not going above about 0.015 g/L = 15 mg/L
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Duer 157099 Donating Member (1000+ posts) Send PM | Profile | Ignore Sun May-01-11 03:28 AM
Response to Original message
4. d) 1.190g n/t

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ChromeFoundry Donating Member (1000+ posts) Send PM | Profile | Ignore Sun May-01-11 05:22 PM
Response to Reply #4
6. Correct - Yay!
Using the following Molar Masses:

 Ca    = 40.0 g * mol-1

 CaCO3 = 100 g * mol-1





(0.500 L) (
0.950 Ca2+
1 L solution
) (
1 mol Ca2+
40 g Ca2+
) (
1 mol CaCO3
1 mol Ca2+
) (
100 g CaCO3
1 mol CaCO3
) = 1.19 g
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Duer 157099 Donating Member (1000+ posts) Send PM | Profile | Ignore Sun May-01-11 06:33 PM
Response to Reply #6
8. I was never good at showing my work
thanks for putting it all down in understandable terms. I know that's how it's supposed to be done, but I never do it that way.
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trof Donating Member (1000+ posts) Send PM | Profile | Ignore Sun May-01-11 06:45 PM
Response to Reply #4
10. I knew that.
I'm pretty sure.
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HopeHoops Donating Member (1000+ posts) Send PM | Profile | Ignore Sun May-01-11 08:07 AM
Response to Original message
5. Kitteh
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elleng Donating Member (1000+ posts) Send PM | Profile | Ignore Sun May-01-11 05:54 PM
Response to Original message
7. Wattsamattayou, dis is da LOUNGE!!!!
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Xipe Totec Donating Member (1000+ posts) Send PM | Profile | Ignore Sun May-01-11 06:42 PM
Response to Reply #7
9. Yea, I didn't do six years of chemistry in college to answer questions in my free time
That's all behind me now.
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valerief Donating Member (1000+ posts) Send PM | Profile | Ignore Sun May-01-11 08:40 PM
Response to Original message
11. Door number three, Monty. nt
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rug Donating Member (1000+ posts) Send PM | Profile | Ignore Sun May-01-11 09:06 PM
Response to Original message
12. What is the mass after consuming 3kg of CaCoa?
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