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  #26  
Old 09/16/2005, 03:34 PM
Habib Habib is offline
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Re: any math gurus around right now.

Quote:
Originally posted by Misfit6669
I am missing something with this one and I can't get it setup right.

How many gallons of distilled water must be mixed with 50 gallons of 30% alcohol solution to obtain a 25% solution?

It shouldn't be hard for me but I am not getting it.
I keep setting it up like this and it's not right

x * .3(50) = x(.25 + 50)

I know why this is wrong, I think. My x is 100%, damn I think I am close but still missing something.
Thanks for any help again.
Brian



Going from 30% to 25% means it has to be diluted by a factor of 30/25 = 1.2 so the volume has to become 50 x 1.2 gallons thus 10 gallons of water have to be added.




A chemist will tell that the above answer is not fully correct because when adding 10 gallons of water to 50 gallons of an alcoholic solution the end volume will not be 60 gallons.

But it is for a math class so 10 gallans have to be added to the 50 gallons.
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  #27  
Old 09/16/2005, 03:58 PM
olkeller olkeller is offline
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habib why is that
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  #28  
Old 09/16/2005, 04:02 PM
Habib Habib is offline
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Quote:
Originally posted by olkeller
habib why is that

If one would mix one gallon of water with one gallon of water then the end volume will be less than 2 gallons.

The water and alcohol molecule interact with each other in such a way that they get packed more closely so take up less space.
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  #29  
Old 09/16/2005, 04:11 PM
jgoodrich71 jgoodrich71 is offline
But what do I know?
 
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So 1+1 does not equal 2?
  #30  
Old 09/16/2005, 04:13 PM
Habib Habib is offline
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Quote:
Originally posted by jgoodrich71
So 1+1 does not equal 2?
1 molecule + 1 molecule = 2 molecules

1 gallon + 1 gallon of something else is not always 2 gallons.
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"LOL, well I have no brain apparently. " - dc (Debi)
  #31  
Old 09/16/2005, 04:43 PM
olkeller olkeller is offline
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thats wierd why is that
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  #32  
Old 09/16/2005, 04:47 PM
Habib Habib is offline
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Quote:
Originally posted by olkeller
thats wierd why is that
What?
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  #33  
Old 09/16/2005, 04:56 PM
olkeller olkeller is offline
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Quote:
Originally posted by Habib

The water and alcohol molecule interact with each other in such a way that they get packed more closely so take up less space.
I posted a chemistry ? in here will you take a look at it and see if you could answer it for me as well
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