Talk:Mole (unit)

"Mole(unit)" listed at Redirects for discussion

The redirect Mole(unit) has been listed at redirects for discussion to determine whether its use and function meets the redirect guidelines. Readers of this page are welcome to comment on this redirect at Wikipedia:Redirects for discussion/Log/2023 November 9 § Mole(unit) until a consensus is reached. Steel1943 (talk) 17:24, 9 November 2023 (UTC)

For the benefit of other editors: the issue is the lack of a space between "Mole" and "(unit)" in the redirect source. Johnjbarton (talk) 17:29, 9 November 2023 (UTC)

Some common misspellings of titles are used as redirects for convenience. I don't know that there is a rule about that. In the case of the space, seems to me that either all such articles should have redirects, or none. Gah4 (talk) 01:41, 29 May 2024 (UTC)

In my opinion this is not at all a common misspelling and it should not exist. Normal users won't search for "Mole(unit)" and internal wikilinks that use Mole(unit) will be red and can be fixed. Johnjbarton (talk) 02:30, 29 May 2024 (UTC)

What is that image trying to say?

Recently this image was added

• Mass versus moles of iron vs gold.svg

It has some boxes and circles with Fe and Au labels. What is it trying to tell us? @VectorVoyager Johnjbarton (talk) 16:49, 6 March 2024 (UTC)

I actually made it for Molar mass page which I think is quite fitting there. It tells that 2 samples of 2 different elements for the same amount of mass that differ in molar mass have different number of moles in the same mass (m/M). I can take it off from this page as its not specifically a diagram to make people understand moles but that it can stay in the molar mass page if there is no errors. I am 100% open for suggestions for improvement though. VectorVoyager (talk) 22:43, 6 March 2024 (UTC)

@VectorVoyager ok thanks. the image has two cylinders and now I notice that they have different sizes. I suppose this much would be clearer to me if they were side by side with text like "same mass, different volume". but I'm not sure how to connect that to the topic. it's just to imagine a visual that works for numbers and mass without involving density. Johnjbarton (talk) 04:47, 7 March 2024 (UTC)

@Johnjbarton: hi, I made a new depiction for this page (Mole carbon-12 diagram.svg). I think something like this is more fitting for the page. Its very important that the visitors understand diagrams used on the Wiki, so I am open for suggestions to improve that previous one that is currently present on molar mass page. How can I make it more understandable in a visual way? Thanks. VectorVoyager (talk) 11:39, 7 March 2024 (UTC)

Well you picked a tough assignment ;-)

My suggestions for this version:

1. Move the 12 grams of ¹²C on to the Mole side
2. Remove the Avogadro (too much)
3. Rather than the ambiguous x602 sextillion, just write 602 sextillion Carbon atoms.

That much illustrates "Mole" but does not pinpoint "Mole (unit)".

For "Mole (unit)" maybe an image with seemingly many items and the amount in Mole? The only thing one need to get a across is that the unit is for counting items and the scale is ridiculously large.

HTH Johnjbarton (talk) 16:40, 7 March 2024 (UTC)

Thanks! I have implemented the first and third suggestions that you have written, but I think stating that the accepted exact form is Avogadro constant is intuitive for the reader to understand the connection between NA and moles. VectorVoyager (talk) 08:40, 8 March 2024 (UTC)

mol kept me from Chemistry

I found the concept of calling some arbitrary number a 'mol' of something exceedingly confusing when I was confronted with it at school. And as it is a basic concept, I got bad grades in my first test. Turns out, I was right, and there are people sharing my criticism. If anyone out there works in curriculum design: Please just leave out this nonsensical non-unit and get into the interesting stuff. Molar masses can be discussed way later, in advanced studies. Thank you. --2A01:C23:5DB9:4A00:B905:825E:E1B0:1A05 (talk) 2A01:C23:5DB9:4A00:B905:825E:E1B0:1A05 (talk) 21:15, 12 March 2024 (UTC)

This is not the place to discuss curriculum design. Pradyung (talk) 00:38, 29 May 2024 (UTC)

Amount is (arguably) the most basic quantity

From time to time, we see publications questioning the need for some of the base quantities of the SI. For example, time, length, mass, and electric charge are always considered fundamental; and recently, angle has been proposed to be added to that list. But temperature is just a convenient way of dealing with (thermal) energy, and could be abandoned, along with its unit. Luminous intensity can be dealt with in other ways. And, in particular for the subject of this Wikipedia article (the unit mole), amount (of a substance) is often claimed to be unnecessary—because we could equally as well deal just with the (dimensionless) number of entities. But "amount" (not to be confused with "mass" or "volume", for which the name "amount" is often used, incorrectly), being an aggregate of a number of entities, is arguably the most fundamental of all physical quantities. If there were no entities (atoms, molecules, photons, &c.) there would be no galaxies, stars, planets, substances, . . . , or sentient beings (and time, length, mass, electric charge, angle—and number—would have no "meaning", and therefore, would not "exist"). For this reason, it is obviously critically important that amount and its macroscopic unit, the mole, be thoroughly understood. Currently, this is one of the two most poorly understood concepts in the STEM curriculum. [The other is anything to do with the now-you-see-me-now-you-don't radian (and its cousin, the steradian)]. Boppennoppy (talk) 22:05, 22 November 2024 (UTC)

@Boppennoppy Please read WP:NOTFORUM, "article talk pages exist solely to discuss how to improve articles" Johnjbarton (talk) 23:54, 22 November 2024 (UTC)

My intention was to begin a gentle conversation (i.e. talk) that would ultimately address the section of this article headed Criticism. Its continued inclusion could give readers the impression that there is something "wrong" or "questionable" about what is often called the "mole concept"—the nature of the physical quantity amount and its macroscopic unit, the mole. However, I'll come straight to the point:

In order to IMPROVE the article, this section should be completely removed, especially in light of the 2019 redefinitions of the SI base units. And here's why.

In essentially all textbooks and online tutorials, stoichiometric calculations (supposedly) employ the factor-label method that involves conversion factors that (when used correctly) are identically equal to one. In stoichiometry, so-called "conversion factors" such as

(6.02 × 10²³ mcl CO₂)/(1 mol CO₂)

where "mcl" is a descriptive label used as a place-holder for the number 1, give the clear impression that a mole is simply another name for the Avogadro number. This is usually reinforced by invoking the analogy with a dozen—another name for the number 12. We also see "conversion factors" like

(44 g CO₂)/(1 mol CO₂)

which (supposedly being "equal" to 1) clearly states that "the mole is a substance-dependent (i.e. "parametric") mass unit—harking back to the pre-mole era of "gram-molecular-weight" or "chemical mass unit". [This "dual nature of the mole", supposedly involving both a "number aspect" and a "mass aspect" has been discussed in an important survey paper tracing the history of the mole by the current Director of the BIPM.]

Among the authors of the papers referenced in the Criticism section, Paul de Bièvre (who made major contributions to chemistry and related fields) was in the "number aspect" camp—that a mole (correctly interpreted as an Avogadro number of entities) is actually a dimensionless Avogadro number of "ones". And this is reflected in the referenced paper. Similarly for the Barański paper. On the other hand, the paper by Ingvar Johansson (a highly respected philosopher of science) is in the "mass aspect" camp—that a mole of a substance X (which has a mass of A_r(X) g) actually is the substance-dependent (parametric) mass unit A_r(X) g. The other referenced papers refer to some aspects of industrial chemistry and minor philosophical points (involving the basic assumptions of continuum mechanics), respectively, that are not significant criticisms of the mole concept itself.

So, to repeat: in order to IMPROVE the article, the section on Criticism should be removed.

Boppennoppy (talk) 16:09, 23 November 2024 (UTC)

I disagree. The Criticism section is referenced and provides an alternative point of view. I also disagree with your characterization of the sources. They all discuss issues with the mole. Maybe you don't consider these to be significant but evidently neither did BIPM. This is a short section which I think has some interest. Johnjbarton (talk) 03:17, 24 November 2024 (UTC)

In an encyclopaedia, alternative points of view or opinions may sometimes have a place—but not (incorrect) "alternative facts". The de Bièvre & Peiser paper is mostly about terminology surrounding the term "atomic weight" and alternatives. Concerning the mole, they give rebuttals to five "objections, mostly centred in Russia", only one of which is significant: "The mole is a count; counting is not measuring". Of course this "alternative fact" is incorrect and equivalent to "1 mol = N₀", the Avogadro number, in which case the Avogadro constant would be "N_A = 1 (exactly)". This is the "number-aspect of the mole" fallacy, and is one of the major reasons for confusion about the physical quantity amount and the mole concept. Johansson's "parametric" unit is equivalent to "1 mol = A_r(X) g", a substance-dependent mass unit. And, of course, this "alternative fact" is also incorrect. This is the "mass-aspect of the mole" fallacy, and is a second major reason for confusion about the mole concept. The Barański paper is not a criticism of the mole itself, but rather mostly about the name for "the-quantity-for-which-the-mole-is-the-unit", which, by now, is irrelevant. The paper by Cooper & Humphry discusses the ontological distinction between continuous and discrete quantities, reviving the "counting-is-not-measuring" idea. They claim that because amount (of a substance) is proportional to a number of discrete entities, it is in the latter category. And thus, that the mole should not be included along with base units for "continuous" quantities such as mass, length, time, and electric current, for example. But mass (of a substance) is no different in this respect from amount—it consists of a number of discrete atomic-scale masses, m(X) = N(X)m_a(X), and nobody seems to "worry" about that (real) fact. Not to mention the same discrete nature of electric charge. At the macroscopic level, the physical quantities number-of-entities, amount, and (substance) mass are all appropriately treated as continuous differentiable variables (because the number of entities is so large). Cooper & Humphry should have known that this is the basic assumption of Continuum Mechanics, related to the resolution of the Sorites Paradox. This paper is a serious Red Herring, likely to cause even more confusion. Gary Price's paper is more a criticism of the SI in general, and might be appropriately included in an article on the International System of Units, but has no place here.

Finally, since you seem to be questioning my "authority" for characterization of the sources, perhaps I should point out that I am (literally) uniquely qualified to comment on the mole (and the kilogram). On June 2nd, 2005, I submitted a letter to the editor of Metrologia, "Note on invariant redefinitions of SI base units for both mass and amount of substance", that was published on December 22nd, 2005, in which I suggest that "a fixed-h redefinition of the base unit for mass together with a fixed-N_A redefinition of the base unit for amount [which would necessitate relaxing the exactness constraint on the molar mass of carbon-12] . . . would be worth considering." The well-known paper by Mills, Mohr, Quinn, Taylor & Williams, which became the blueprint for the redefinitions of SI units, incorporating the fixed-h kilogram and fixed-N_A mole, was submitted on January 4th of 2006 and published on April 6th.

Please eliminate the distracting and potentially confusing section on "Criticism".

More importantly, a section on the well-documented widespread confusion about the mole concept (and why this continues to occur) should be added in order to improve the article. Boppennoppy (talk) 19:11, 24 November 2024 (UTC)

Sorry, but we cannot cite your qualifications. If you have reliable references which challenge any source in the article we can include the alternative point of view. Any of reliable references on "well-documented widespread confusion" can also be added. Please see WP:VERIFY Johnjbarton (talk) 19:31, 24 November 2024 (UTC)

I have pointed out in detail why keeping the section on Criticism could reinforce some of the confusion surrounding the mole concept. There is no "number aspect" to the mole; specifically, it is not the Avogadro number. There is no "mass aspect" to the mole; specifically, it is not "the atomic weight in grams". Just as there is no "number aspect" or "amount aspect" to the kilogram. The mole is the SI base unit for amount. Amount is related to the number-of-entities via the Avogadro constant, and related to mass via the molar mass—just as mass is related to acceleration via Newton's Second Law and related to force via a gravitational field, for example. Science teachers go to great lengths to dispel any possible confusion between mass and weight, and their respective coherent units kilogram and newton. An encyclopaedia article on the unit for amount should go to similar great lengths to avoid any (further) confusion about amount, number-of-entities, and mass, which are three very different physical quantities.

Perhaps you could justify your opinion that this section has "some interest" (to the general reader or beginning STEM students?) and should be kept as is—by being much more specific about each of the referenced sources.

Otherwise, please remove this section. Boppennoppy (talk) 17:48, 25 November 2024 (UTC)