<filthy_peasant> what's confusing you on it?
<Polesch2> My lab manual also asks me to find the partial molar volume of water using that formula, but .. it increases with highet fraction of ethanol? Opposite of what makes sense.
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<filthy_peasant> you mean when you have trace amounts of water added to your ethanol, it has a significantly larger volume than you'd expect it would (if they were pure)?
<solol> what is density used for in chem
<Polesch2> I need to calculate the partial molar volume of ethanol for 0%, 20%, 40%, 60%, 80% and 100% solutions
<Polesch2> I have their density.
<solol> how is density measured
<Polesch2> Weight / volume
<solol> i guess i knew that
<solol> what is MWt
<Polesch2> According to the text, the molar mass, i.e. 46 g/mol for ethanol
<Polesch2> MW = molecular weight, MWt .. Molecular WeighT?
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<filthy_peasant_> sorry
<filthy_peasant_> disconnected
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<filthy_peasant_> i'm back now
<solol> how do you use g/mol / m/v?
<naf> is the percent concentration m/m or v/v or m/v ?
<Polesch2> 0,99777  0,97383 0,94046  0,90141  0,85784  0,80838
<Polesch2> mass.
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<solol> V = MWt / density
<filthy_peasant_> polesch2, the water will interact with the ethanol in different ways than it will interact with a pure solvent.  This results in different volumes.
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<Polesch2> Yes..
<filthy_peasant_> Consider the environment of a trace amount of water in ethanol.  A water molecule would be completely surrounded by ethanol in this case.  Vs normally being surrounded by water molecules.  it might have different interactions in that regard.  hydrogen bonding is a huge part of water's interactions
<filthy_peasant_> and it will try to align itself to hydrogen bond
<naf> What's the density of the 20% solution Polesch2?
<filthy_peasant_> i'm not sure if i'm answering your question, because i disconnected and lost part of the conversation and what you were asking
<filthy_peasant_> when it is in a different solution, it will have to align itself in a different way to hydrogen bond with the ethanol, resulting in a different volume