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Chemistry Forums for Students => Analytical Chemistry Forum => Topic started by: calstat on October 08, 2010, 05:38:33 PM

Title: Specific Gravity of Mixtures
Post by: calstat on October 08, 2010, 05:38:33 PM

Hi..

     I am a statistician working on some problems requiring some specific gravity (SG) calculations.

Say I I have water SG=1 and some salt SG=x.  Is there way to find the SG of the mixture

either when the salt is z% by weight or z% by volume?

Any reference will of great help. My google search yielded results on slurries (http://www.gouldspumps.com/pol_0015.html)   I am not sure if the same is applicable to solution with soluble particles.

Thanks

Sam

Title: Re: Specific Gravity of Mixtures
Post by: Stepan on October 08, 2010, 10:33:24 PM

I haven't heard about a general law or formula. You cam estimate two margins. The density (or specific gravity - with this crude estimation it does not make a difference)  it is less than: SG<(M(H2O)+M(Z))/VH2O. The second margin: SG>(M(H2O)+M(Z))/(V(H2O)+V(Z)). More accurate method is to use empirical formula, sometime you can find them for particular salts, or generate linear or quadratic approximation from handbook data.