greenyppols
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is this right?
I boiled some acid from NAPA to see how concentrated I could make it.
100 ml H2SO4 weighs 177.5g at room temp (25ºc)
That is a density of 1.775 which is around 83-84% H2SO4, correct? The density chart in Vogels didnt have a "1.775" so I guesstimated.
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enhzflep
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You'll have to do a spreadsheat yourself to check, since I don't recall exactly. And may in fact, entirely screw this up.. Not to mention that
I'm too lazy to correct the formula, as I assume that 100% has a s.g of
1.84, as opposed to the 98% having that s.g
1) Input weight of 100ml ( A )
2) Vol ml (Acid) = (A-100)/0.84 ( B )
3) Vol ml (Water) = (100-B) ( C )
4) Weight Acid = B*1.84 ( D )
5) %Weight (Acid) = (100*D) / (C+D) ( % Acid by weight )
Now this is obviously incorrect, as I'm assuming 100% H2SO4 has the density of 98% H2SO4, however this has been sufficient for my calculations.
Following these equations,
Density of 1.775 = 92.3% Vol & 95.6% Weight.
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greenyppols
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hmm. So I was off quite a bit. Thanks enhzflep
Anyone able to point me in the direction to explain those calcs and figuring out BPs? I had read here somehere (couldnt find it) that a convenient way
to calculate was to weigh out 100ml.
I was looking through info at brinkmann's site, and a formula was there where "b" was a constant. How does one figure out a constant for a substance?
Say..Benyl Chloride? Is there a list somewhere?
This was for figuring BPs under vacuum, I think.
P = 3.006 - (Ts-Tp)/(b*Tp)
P= vac pressure
Ts=BP at 1013mbar
Tp=vapor pressure temp at pressure P
b=constant b
Im no math whiz (or whiz at anything else, for that matter. lol) but I can muddle through ok enough with a pencil and calculator if I can make heads
or tails out of where to get the info I need and how to use it.
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enhzflep
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As far as Boiling Points go, I have 3/5 & 5/8 of no idea... 
However, for the density of the sulfuric, I just bashed out
values by hand, then determined the relationship between
them from there.
Using an excell spreadsheet, or just some columns on a piece of paper
I went about it like so.
1) 1st column titled Acid volume, contains the numbers 0 to 100
2) 2nd column titled Water volume, contains the numbers 100 to 0
3) 3rd column titled weight, contains and addition of the first two columns.
i.e (1.84 * column1) + (1.0 * column2)
Now by simply reading from the weight column, you can straight away tell
what the % concentration by volume is.
You may choose to add an extra column
labeled "% Acid by weight"
this column has ((column1*1.84) / column 3) entered into it.
e.g
| Code: |
Acid Vol Water Vol Weight % Acid by weight
00 100 100 00.00
10 90 108.4 16.97
20 80 116.8 31.51
30 70 125.2 44.09
40 60 133.6 55.09
50 50 142 64.79
60 40 150.4 73.40
70 30 158.8 81.11
80 20 167.2 88.04
90 10 175.6 94.31
100 00 184 100.00
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pls excuse crappy table (all done with windoze calc.exe) Am running late - this should give you the idea.......
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Antwain
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Are you assuming that the density changes linearly? Its not even close... IIRC the 90% acid has about the same density as the 100% acid, the density
being greatest between these values. Also it goes to all hell for low concentrations due to effects corresponding to 'hydrates' of the acid.
Apparently these cause rather large inflections in the curves for density, vapor pressure, mp. etc.
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