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Topic: molarity question  (Read 3306 times)

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Offline oly40

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molarity question
« on: February 10, 2008, 04:27:54 PM »
An automobile antifreeze contains equal volumes of ethylene glycol (ethane 1,2-diol, d = 1.114 g/mL) and water (d = 1.00 g/mL) at 25C. The solution has a density of 1.06 g/mL. What is the molarity of ethylene glycol in the solution?
(a)   5.88       (b)   4.50    (c)   0.323       (d)   9.00          (e)   8.87

My attempt: For this question, I disregarded the densities for water and the final solution. I just used the density of the ethylene glycol, divided it by 2 (because it is a 50:50 solution, found the number of moles of that, which is also the molarity in the solution. The answer that I got is 8.97 M but none of the choices is that answer. Also, I think I did something wrong because I didn't use all the information in the question.

Thanks

Offline enahs

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Re: molarity question
« Reply #1 on: February 10, 2008, 04:59:19 PM »
You can not ignore the density. You have equal volumes, but each volume has a different mass.

How many mL of antifreeze is in 1 L of the solution? What is the mass of that amount of antifreeze? How many mosl is that?


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