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Topic: Dilutions  (Read 3357 times)

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Offline brycewchilds

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Dilutions
« on: May 20, 2010, 11:03:56 AM »
Hello! I need help with a dilution. I've got KoH in ethanol .5N that needs to be diluted to KoH in ethanol .05N. I've got the ethanol to do the dilutions. Can someone tell me how to do it?  Thanks!!!

Offline sjb

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Re: Dilutions
« Reply #1 on: May 20, 2010, 12:13:48 PM »
What is the definition of N ?

Offline rtblue

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Re: Dilutions
« Reply #2 on: May 20, 2010, 08:50:01 PM »
I am going to assume that your N is actually M, because I see no other solution to this problem.

From the formula M1V1=M2V2, we have the the (initial molarity)(initial volume)=(final molarity)(final volume)

therefore:

to convert the .5M ethanol to .05M ethanol, you will plug it into the equation.

.5M for the initial molarity, however much volume of the .5M you have for the initial volume, .05M for the final molarity, and how much .05M you want to end up with for the final volume.

just add the V(final)-V(initial) water, and then add the initial .5M solution, mix, and you will have a .05 solution.

Offline sjb

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Re: Dilutions
« Reply #3 on: May 22, 2010, 06:20:39 AM »
I am going to assume that your N is actually M, because I see no other solution to this problem.

There's nothing intrinsically wrong with N, as far as I know it is a measure of concentration. Look into normality of solutions, perhaps.

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