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Offline zeshkani

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quick question
« on: April 22, 2008, 12:12:17 AM »
i just have a quick question, this might be so silly  ;D

it says calculated the volume needed from the percents and densities for an FTIR experiment
how much ehtanol is needed to make a 20mL of a 0.5136[M] Ethanol solution whose percent purity is 100%

would this just be take the [M] x Volume(0.02L) = Moles x MW(46.07g/mol)/Density(0.7904g/mL) which will give me volume of ethanol needed then just dilute to 20mL right ??

Online Borek

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Re: quick question
« Reply #1 on: April 22, 2008, 03:20:25 AM »
20mL of a 0.5136[M] Ethanol solution whose percent purity is 100%

Something is wrong with the question - 0.5136M ethanol is not 100% pure.

Could be you are right.
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Offline JGK

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Re: quick question
« Reply #2 on: April 22, 2008, 01:18:16 PM »
20mL of a 0.5136[M] Ethanol solution whose percent purity is 100%

Something is wrong with the question - 0.5136M ethanol is not 100% pure.

Could be you are right.

I think the question should be more correctly phrased as follows:

"What volume of 100% pure ethanol is needed to make a 20mL of a 0.5136[M] Ethanol solution."

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Offline zeshkani

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Re: quick question
« Reply #3 on: April 22, 2008, 01:20:49 PM »
yeah your right, sorry for the confusing question.

so yeah we need to figure out how much 100% ethanol to use to make a 0.5136M Ethanol Solution
but is the way i described it right in my first post or em i totally off

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Re: quick question
« Reply #4 on: April 22, 2008, 01:31:30 PM »
OK, although you abused equal sign :)
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