I spoke to a chemical supplier today and he posed the same question.
I asked him to spell the word that we are discussing here and he spelled out "Mol". I asked the difference and he said it was a bit hard to explain, so he went on to quote prices for both 5 and 10 Mol Borax (The 5 Mol is 50 cents more per 50 pounds). I decided to investigate on my own.
To start Mol is short for Mole, which is a unit of measure of Molar Mass. (Please go to bottom of post to get more detail)
Being inquisitive I managed to track down a scientist at Rio Tinto Borax and asked what the difference is between the two products. He explained that chemically the two are identical. The difference is that the 5 Mol product has 5 less Moles of water in it's elemental makeup.
What does this mean? It means that with less water content the 5 Mol is more concentrated...but at the cost of solubility. I asked for a real world conversion of one product to the other and he stated that 4 pounds of 5 Mol is equal to 5 pounds of 10 Mol. Interesting.
I asked what variation was sold at the supermarket under the Twenty Mule Team name and he said 10 Mol, powder......you see it can be purchased in powder or crystalline form. The powder being more soluble that crystal.
So, it seems to me that the 5 Mol powder may be the best bang for the buck. A distinction may have to be made for the Apple Sauce recipe
Hope this helps.
From ABOUT.com:
"The Mole
A mole is defined as the quantity of a substance that has the same number of particles as are found in 12.000 grams of carbon-12. This number, Avogadro's number, is 6.022x1023. The mass in grams of one mole of a compound is equal to the molecular weight of the compound in atomic mass units. One mole of a compound contains 6.022x1023 molecules of the compound. The mass of 1 mole of a compound is called its molar weight or molar mass. The units for molar weight or molar mass are grams per mole. Here is the formula to determing the number of moles of a sample:
mol = weight of sample (g) / molar weight (g/mol)"
