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Topic: molar concentration! need help fast !  (Read 5002 times)

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Offline asmeet

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molar concentration! need help fast !
« on: June 16, 2010, 12:16:27 AM »
can someon please help me with this ! i dont knwo whats the right answer

A solution is prepared by dissolving 3.0 g iron(II) chloride (MW = 126.8 g/mol) with 75.0 mL of water. The density of the solution is 1.21 g/mL and the density of water is 1.0 g/mL. A student takes 10.0 mL of this solution and dilutes it with water to 250 mL (3 SF). What is the molar concentration of chloride ion in the diluted solution?


a. 0.030 M
b. 0.26 M
c. 0.73 M
d. 0.64 M
e. 0.13 M

Offline opti384

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Re: molar concentration! need help fast !
« Reply #1 on: June 16, 2010, 09:19:49 AM »
You should first start with determining the molar concentration of the Iron(II) chloride solution before diluting.

Then, find how many moles of Iron(II) chloride will be in 10 ml of the solution and then calculate the molar concentration with total 250ml of water.

Offline JGK

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Re: molar concentration! need help fast !
« Reply #2 on: June 16, 2010, 01:21:16 PM »
Is this really an undergraduate level question  ???
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