Talk:Mass fraction (chemistry)

Merge from Percentage solution
Percentage solution and Mass fraction (chemistry) seem to deal with basically the same topic, and both are way too short to justify forking. A merge perhaps? Mikael Häggström (talk) 15:24, 21 March 2011 (UTC)

In general, merging two very short and similar articles makes sense. However, I see a problem here: "Mass fraction" is a well-defined quantity (see IUPAC definition), whereas "percentage solution" seems to be some imprecise term apparently used by biologists. I fear that merging the articles will only increase confusion. I make an alternative suggestion: Convert "percentage solution" into a disambiguation page with 3 entries: RolfSander (talk) 19:40, 22 March 2011 (UTC)
 * if mass/mass "w/w" is meant, then link to mass fraction (chemistry)
 * if mass/volume "w/v" is meant, then link to mass concentration (chemistry)
 * if volume/volume "v/v" is meant, then link to volume concentration

weight percent terminology
Claiming that the terms "weight percent" or "weight-weight percent" are obsolete ignores the fact that they are quite widely used in industry to refer to mass fraction. While I understand encouraging using true IUPAC nomenclature, the "obsolescence" of these terms should not be mis-represented — Preceding unsigned comment added by Ohenn (talk • contribs) 22:17, 10 February 2012 (UTC)
 * You're right, "obsolete" is wrong. It should be "deprecated".--RolfSander (talk) 13:03, 11 February 2012 (UTC)

Mass percentage
Note that mass percentage (also called mass percent) is not the same as mass fraction. They differ by a factor of 100, see "Related quantities".

Regarding the improper name percent concentration, to add to the confusion, take a look at percentage solution.--RolfSander (talk) 07:54, 30 August 2012 (UTC)
 * Thats not correct. The do not differ by the factor of 100.

50% = 0.5 So the symbol % just means "divided by 100", as shown in the [|wikipedia article here]. — Preceding unsigned comment added by Humanlike2015 (talk • contribs) 15:02, 3 April 2018 (UTC)

Mixing ratio
The mixing of two pure components can be expressed introducing the (mass)mixing ratio of them $$r_m = \frac{m_2}{m_1}$$. Then the mass fractions of the components will be:


 * $$w_1 = \frac{1}{1+ r_m}$$
 * $$w_2 = \frac{r_m}{1+ r_m}$$ — Preceding unsigned comment added by 82.137.8.113 (talk) 00:09, 12 August 2016 (UTC)

The realtion gets rather interesting or non-trivial starting with ternary mixtures.--82.137.8.113 (talk) 00:13, 12 August 2016 (UTC)

What do "w/w" and "% w/w" mean?
The redirect redirects to this article, and Percentage solution says to come to this article for an explanation of "% w/w". But I find no explanation of what is meant by these expressions in this article. Does "% w/w" mean the same thing as "wt%"? Is there an explanation somewhere else on Wikipedia? Should an explanation be added to this article?

For example, if a saline solution has a salt content of 20% w/w, is that 20% salt mass per unit of mixed saline solution mass or 20% salt mass per unit of water mass? Assuming it is the former, I just edited the article to say it.

—⁠ ⁠BarrelProof (talk) 22:13, 21 August 2023 (UTC)


 * Yes, indeed. Like "wt%", "% w/w" is just another way to (incorrectly) describe mass fraction.


 * Yes, the denominator refers to solution, not to water. This is already mentioned in the first sentence of the article: "...total mass ... of the mixture...".


 * --RolfSander (talk) 10:43, 23 August 2023 (UTC)