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shortandsmall
Mar 1, 2009, 09:07 AM
:confused:

Can anyone help me find a chemistry flow chart? I really need it to be really easy to read because I don't really understand moles very much. Thanks so much.
Ps:
It has to have volume, mass in grams and numbers of particles, atoms and particles


Thanks so much

Perito
Mar 1, 2009, 05:12 PM
The Periodic Table of the Elements has almost all of this (or maybe more). Otherwise, you need to go to something like the "rubber handbook" (The Handbook of Chemistry and Physics) or another reference. I've never seen a chemistry flow chart, and I'm not sure it would do any good if you had one.

There isn't anything to understanding moles. 1 mole (1 gram-mole) of a substance contains 6.023 x 10^23 molecules (or atoms, if it's not a compound) of that substance.

To determine the mass of a mole (gram-mole, actually) of these atoms, you simply calculate the formula weight by looking at the periodic table of the elements. Take the atomic weight for each atom and multiply that by the number of atoms in the molecule. That will tell you the "formula weight" or the "molecular weight". The formula weight is always equal to the molecular weight unless you don't really know the number of atoms in a molecule and you assume wrongly or you don't have enough information to determine. For example, Ethane is C2H10. If someone thought that it was CH5, the formula weight (of CH5) would be 17. The actual molecular weight would really be 34.

If you wish to know how many moles of a substance there are in a given weight, just recognize that the molecular weight is "grams/mole". If you divide "grams" by "grams/mole", the grams cancel out and you're left with "mole"(s). So, all you have to do is divide the mass (in grams) by the molecular weight (in grams/mole).

If you have the mass of something (in grams) and have the density of that substance in (g/mL), you can find the volume of the substance by dividing grams by grams/mL. Grams cancel out and you're left with mL (sometimes written "ml" for milliliters).

You can convert the mass or volume between different systems of units.