What is the history of the mole? Who came up with it? Why was it created? Wats the actual # for a mole? When was it created? What does it mean? Why is it important to chemistry and people? Lots of thx :)
well I dont know who came up with it or anything about the history but it is the number of molecules, so for example a potassium permanganate solution that has a concentration of 3 moles per litre has three molecules of potassium permangate for each litre of water. The molecular weight is generally on the periodic table and you just combine the numbers for all the elements in a compound (keeping in mind the stoicheometry!) to get the molecular weight of a compound.
Number of moles = mass (grams) divided by molar mass Molar mass = mass divided by number of moles mass = number of moles multipled by molar mass
for concentrations of solution... number of moles = concentration multiplied by volume concentration = number of moles divided by volume volumes = number of moles divided by concentration
the concentration of a solution is expressed as moles per litre (moles L-1)
Hope that helps a bit. Its one of those things that once you get your head around it, its not too hard so keep trying! If I remember correctly its all based on carbon or something...
I know I just don't understand any of that mole crap. BUT, it's a measurement and this is what my revision notes said... Definition: a chemical mass unit, defined to be 6.022 x 10(to the power of 23) molecules, atoms, or some other unit. The mass of a mole is the gram formula mass of a substance. Examples: 1 mole of NH3 has 6.022 x 1023 molecules and weighs about 17 grams. 1 mole of copper has 6.022 x 1023 atoms and weighs about 63.54 grams.
SO sorry if this doesn't help, but try and learn it - I did, and got an A in my chemistry GCSE.