Help to make solution calculation

[Chemist ZL]

I am making solution that is not very diluted. For example, 1L 4M NaCl
water solution. I used to run approximate calculation to ignore
solute volume. i.e. 1 Liter water plust 4x MW=4x58.443=233.77g of
NaCl.

However, now I need more accurate method to calculate solvent and
solute. I came accross a web site that claims it gives more accurate
results (with ideal solution model ??). The solvent water calculated
is now ~892ml with same amount of NaCl (~233 grame). This is much
different from the value I got before. I am not sure how much it is
reliable.

Can any of you give comment about that? The web site is at
http://www.popproperty.net/PopularTools/SolutionMaker.aspx?Dilute=0

Thank you in advance!

[Poutnik]

In article <357eb80b-6857-49b9-9b67-469eb2940ed2
@m7g2000prd.googlegroups.com>, ***@yahoo.com says...

Post by Chemist ZL
I am making solution that is not very diluted. For example, 1L 4M NaCl
water solution. I used to run approximate calculation to ignore
solute volume. i.e. 1 Liter water plust 4x MW=4x58.443=233.77g of
NaCl.

I would not call it approximation, rather a mistake.
On one hand you take precission of 5 digits,
OTOH you ignore the fact FINAL volume is to be 1 liter,
what leads to a big error in concentration.

If dilution to final voluume is not suitable for regular preparation,
you can do it at least once and weight or measure volume of water,
needed to fill the calibrated 1L flask.
( final filling after all is diluted )

OR, with less accuracy, calculate volume of the solid NaCL,
and substract it from 1L, getting needed volume of water.
But this method does not count volume changes during dilution.

I will not belive much to general calculations,
especially if exact values are needed.
( If not needed, there is no use to weight so precisely )

[Poutnik]

In article <357eb80b-6857-49b9-9b67-469eb2940ed2
@m7g2000prd.googlegroups.com>, ***@yahoo.com says...

Post by Chemist ZL
Can any of you give comment about that? The web site is at
http://www.popproperty.net/PopularTools/SolutionMaker.aspx?Dilute=0

when checked their calculation, they count volume of the salt from
weight and density, and then calculate volume of water.

So, this method is approximation, as I mentioed, not counting
with volume change while dilution. If you can afford this,
it is calculation for you.