Calculating Solubility?

[BeeStar]

How do I calculate the solubility of a substance? Give me a "dummy" version, please. I searched the internet but the explanations were too complex for me to understand

 

[Koot]

Solubility is usually measured in grams over some solvent. Generally water.

So a solubility of something would be like

50g of NaCl / 1kg H2O.

That's probably wrong as I just made up some numbers.

 

[BeeStar]

Hmm, so why is it that on websites I see stuff like 1.6 * 10^-2 M?

Source: http://www.chem.queensu.ca/people/faculty/mombourquette/firstyrchem/solubility/index.htm

 

[malyce]

The M is just a unit of weight, in the case of chemistry (and some physics, specifically thermal) it is called the "mole."

1.6x10^-2 is just .016Moles or .016M

the x10^-2 is just scientific notation. All it means is to move the decimal place forward two zeros, or to move the 1 to the hundreds place.

1.7x10^3M would be 1.7Kilomoles, or 1700moles.

A mole I believe is a universal measurement of a liquid or a gas. I'm not 100% on that since I don't specialize in thermal dynamics.

More information on the mole: http://en.wikipedia.org/wiki/Mole_(unit)

 

[BeeStar]

I see, it makes sense ... but 1.6 * 10^2 moles, for example ... as Koot's example is (solid)/(liquid), and Mole is apparently just a unit of mass, where's the fraction? >.<

Sorry if that doesn't make sense..

 

[Koot]

Don't listen to what malyce said.

M and moles are completely different things.
M is molarity which is the concentration of a solution. Moles is kinda of another way of expressing how much "stuff" there is.

Solubility and concentration are somewhat related but they aren't directly used with each other.

Moles is the amount of grams of the the substance divided by the weight of the substance.

Then molarity is the moles of that divided by the amount of solvent there is, usually 1 liter.

Might be a bit too much so ask if you're still confused.

 

[malyce]

Don't listen to what malyce said.

M and moles are completely different things.
M is molarity which is the concentration of a solution. Moles is kinda of another way of expressing how much "stuff" there is.

Solubility and concentration are somewhat related but they aren't directly used with each other.

Moles is the amount of grams of the the substance divided by the weight of the substance.

Then molarity is the moles of that divided by the amount of solvent there is, usually 1 liter.

Might be a bit too much so ask if you're still confused.

He's probably right, as I said my specialization is nothing involving chemicals.

Thanks for the correction, Koot. I don't mean to mislead people

 

[Koot]

Now you can learn something too!

 

[BeeStar]

All right, I get it now, thanks guys. Problem is, I just remembered that I don't need to now this **FACEPALM** thanks anyway