Just in reply, as this was the thread which brought me to join the site.
"And finally Nanomole. Nano + mole - anyone can work out what that is, a tiny fraction of a mole. Giga is 109, Nano is 10-9, and the mole is the weight of 12g of Carbon-12 atoms, which is (something like) 6.0221×1023 particles of C12. However you don't need to know that, as that number is Avogadro's constant, a mole is simply 12g of an element or compound. So it's not a number used for counting, it's a weight. Do you see "grams" or any other unit in the question? No, so you can eliminate it right away once you know it needs a unit to be meaningful. A nanomole is 1.2*10-8 grams."
This is actually incorrect. A mole is a measurement of constituents (e.g., atoms or molecules) within a given substance, which equals Avo's number c. 6.02×10^23. It is only a fixed mass with reference to a specific substance, and therefore only equal to 12g when the substance is the C-12 isotope of carbon. Generally, we use a mole to be representative of the average atomic weight in grams, although it's simpler and more reasonable to use the atomic number for most basic calculations.
An easy way to understand this is if one mole of sodium reacts with one mole of chlorine, the yield is one mole of sodium chloride ions, rather than two moles, as the resulting salt contains the same number of ions as there are atoms in each of the reactants.
Hope this helps
"And finally Nanomole. Nano + mole - anyone can work out what that is, a tiny fraction of a mole. Giga is 109, Nano is 10-9, and the mole is the weight of 12g of Carbon-12 atoms, which is (something like) 6.0221×1023 particles of C12. However you don't need to know that, as that number is Avogadro's constant, a mole is simply 12g of an element or compound. So it's not a number used for counting, it's a weight. Do you see "grams" or any other unit in the question? No, so you can eliminate it right away once you know it needs a unit to be meaningful. A nanomole is 1.2*10-8 grams."
This is actually incorrect. A mole is a measurement of constituents (e.g., atoms or molecules) within a given substance, which equals Avo's number c. 6.02×10^23. It is only a fixed mass with reference to a specific substance, and therefore only equal to 12g when the substance is the C-12 isotope of carbon. Generally, we use a mole to be representative of the average atomic weight in grams, although it's simpler and more reasonable to use the atomic number for most basic calculations.
An easy way to understand this is if one mole of sodium reacts with one mole of chlorine, the yield is one mole of sodium chloride ions, rather than two moles, as the resulting salt contains the same number of ions as there are atoms in each of the reactants.
Hope this helps
