As you know 100 ml of H2O mixed with 100 ml ethanol is not 200 ml

What is the official name of this 'volume loss'?

Is it possible, and if so, how, to calculate, before mixing, what the density of a mixture of (polar) fluids will be? Temperature can be ignored.

Is there a fitted function to estimate this?

Edit. Since the volume loss depends on the reagents, we narrow it down to two components which do not have a chemical reaction between themselves. H2O and Ethanol. What happens with 199 ml H2O and 1 ml Ethanol. Or 100 ml and 100 ml, or 50 ml and 150 ml?


  • $\begingroup$ You need to know the chemical reaction that occurs between them and the change in density of the products due to that. This seems like a simple chemical reaction question $\endgroup$ Nov 13, 2019 at 11:41
  • $\begingroup$ I wonder whether there is a correlation between the change in volume and exo/endo-thermicity of mixing. $\endgroup$ Nov 14, 2019 at 13:38
  • $\begingroup$ This page has good info on the subject mathscinotes.com/2016/07/… $\endgroup$
    – Doege
    Nov 19, 2019 at 7:20

1 Answer 1


Discrepancy between ideal and real property is called Excess property and in this case excess volume.


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