Talk:Solubility table

The compounds are arranged in alphabetical order, but the names aren't visible. Also, there is no information on organic compounds in water.

At what temperature was the volume(100ml) of the water taken? It varies with temperature.

Is the solubility in grams per 100 mL of water, or grams per 100 mL of solution? This matters.... RobertAustin 11:37, 28 September 2006 (UTC)

References?

Should there be references/sources for these values? -- 12.4.81.145 14:13, 14 August 2006 (UTC) Yep, but alot of wikipedians are as I put it "Article Demons" they will just change anything they don't like for no reason and don't give a shit about refrences. They only care that thier view is heard and everone elses is covered up. Then there are the good wikipedians, who do what they should, but the Article Demons will come back and ruin it all.

Perhaps the following link to the IUPAC-NIST database of solubility will help: [1]

Fuzzform 19:58, 27 October 2006 (UTC)

NH4NO3

The article for NH4NO3 says solubility is 190g/100ml at 20 degrees Celsius, but this table says 192g/100ml. Which is it? Why isn't any of this cited? Alex Dodge 07:01, 30 October 2006 (UTC)

Missing compounds

I am researching everything I can about sugar, which is sucrose. It's not in the solubility table, but salt (NaCI) is. What is going on here?17:20, 9 December 2006 (UTC)

RE: Missing Compounds

If you might notice it says inorganic compounds (ie. compounds without carbon). Sucrose contains carbon therefore it is not in the list.

Thanks for clarifying. I feel pretty dumb now! --Gabycs 00:12, 22 March 2007 (UTC)

dumb

Well, these data are foolish. If they list it by mass, then of course the heavier salts will bear a greatter "solubility". But that's not what solubility should be; it should be a ratio of volums or at least moles. -lysdexia 19:43, 5 January 2007 (UTC)

Solubility

Heavier salts do not have a higher solubility, in fact many of the heavy metal salts are insoluble. And solubility is defined (g/100ml H2O). It is not yours to decide which is right.

The solubility should be (grams/100grams H2O) as the volume of water changes with temperature.

OMG water mass (and conseq weight) also changes with temp. The most correct is mol of subject /mol of the solvent

OMG water mass (and conseq weight) also changes with temp. The most correct is mol of subject /mol of the solvent —The preceding unsigned comment was added by 62.176.6.129 (talk) 21:48, 16 March 2007 (UTC).

Mass does not change with fluctuations in temperature

The mass of a fixed volume of liquid does change with temperature! That's why many solubility tables give the solubility per mass of solvent, rather than volume. --Itub 18:30, 26 March 2007 (UTC)

Mass is a measure of matter and is nonvariable. Therefore, it does not change with variations in temperature. If it did, then the number of moles of a substance would also change, which is obviously not true

I'm afraid you are not getting the point, so let me be more explicit. Let's assume you have 1000 mL of water at 4 deg C, which is 1000 g of water. Now you heat your water to 30 deg C. The density decreases, so the volume expands. Now you have about 1004 mL of water. It still weighs 1 kg, of course. But if you measure the solubility now in g/L, you'll be measuring the solubility for about 996 g of water, which is a different amount of solvent. To avoid this effect, it is better to measure the solubility as mass of solute / mass of solvent, or moles / moles. --06:24, 3 April 2007 (UTC)

You're thinking of weight 24.141.46.113 (talk) 21:13, 22 April 2008 (UTC)

My comments on above comments

There's absolutely no use arguing about units (M or g/100cm³). The unit is given in the description. This is because g/100cm³ is the most common unit found for "solubility" on the web. If you want it in molarity, do the calculation yourself. Or if you would like to benefit others like me, go do all the calculation and post it here, give the values beside with a slash in between, or make a separate table on your own.

For accuracy, most of you should have heard it by now, that solubility, as well as solubility product constants, cannot be very accurate as very minor factors such as water purity or dissolved carbon dioxide may interfere. Common factors include:

water purity / dissolved CO₂ (as for CaCO(sub>3 due to common ion effect; NaOH by neutralization)

efflorescence (as CuSO₄.5H₂/ deliquescence (as for FeCl₃)

decomposition in water (as for some sulfides and oxides)

formation of complexes (as CuCl₂, most iron(III) salts)

temperature change when the substance dissolves in water (e.g. CaCl₂, NaOH)

It is true that water changes its volume with temperature, but the effect is insignificant when compared to the above factors. Therefore many (including here - the solubility table) choose to use the unit g/100cm³. Moreover, here I have chosen this unit, as well as the values, together from the source. It is not to me to decide how to change the unit. Maybe those who gave these values measured water in cm³ rather than in g! Who knows! Keep the units. Don't change it. (And water mass does not change with temperature, unless it evaporates and slips away, an error of which can be experimentally eliminated fairly easily)

For heavier salts being more "soluble", this is indeed foolish. Solubility is determined by many factors, including lattice energy, stability of the ions in solution, amongst many others. Simply relating the solubility of a particular salt directly to how dense it is (not how heavy, as larger chunks are heavier than small crystals) reveals conceptual problems in the basic principles of not only chemistry, but general science. The idea of ratio of volumes is even absurd.

For sugars and other organic compounds, if anyone finds them, add them to the list. I'm too busy with exams and projects right now. And if I do have time, I'll fix the references first. They don't seem to be precise enough, and I'm sorry coz I didn't realize the importance of citing sources when I was gathering the data. I'm planning to cite those I know where they come from, and probably deleting those without known sources or substituting with other values that have a source. Hopefully all this can be done in July, after my exams.

Anyway, hope this table's useful.

Thanks to everyone who helped.

Chiu frederick 10:58, 18 May 2007 (UTC)

Ksp of inorganic carbonates at various temps.

In order to alleviate the crystallization problem, I'm trying to avoid/minimise the formation of sodium carbonate crystal due to reaction with the CO2 presence in the atmosphere in a chlorine scrubber system.

Can anyone provide a list of Ksp values for carbonates such as Na2CO3 and K2CO3 at various temperatures similar to the solubility table? Most appreciated.

A202.128.229.48 05:51, 22 May 2007 (UTC)

Re: Ksp of inorganic carbonates at various temps.

Ksp values are not accurate for such soluble salts as Na2CO3 and K2CO3, but you can do the calculation:

Ksp = [Na⁺]²[CO₃^2-]=4[CO₃^2-]³=4[Na₂CO₃]³

the same for K2CO3

Chiu frederick 05:38, 18 June 2007 (UTC)

25° C

Virtually every reference I find lists the solubility of a compound at 25 degrees - which makes sense aince most room temperatures are close to 25 Celsius. Anyone else think we should had 25° to the list? Thricecube 07:58, 25 July 2007 (UTC)

Like Robert Austin mentions whether the data is based on 100 ml of water or 100 mL of solution is is vital fro salts with high solubities. If the author could add a line stating the basis of the solubilities that would be much appreciated.

Just looking at the data itself ...the oxygen data stuck out as odd. It appears to be based on air and one litre rather than 100 mL??...Thanks —Preceding unsigned comment added by 207.102.244.253 (talk) 17:07, 12 February 2008 (UTC)