What is Avogadro’s number? And what are its units?
144090
6.022 x 10^23\n \nIt's named after Lorenzo Romano Amedeo Carlo Avogadro, conte di Quaregna e di Cerreto (1776 - 1856).\n\nThe name "Avogadro's Number" is just an honorary name attached to the calculated value of the number of atoms, molecules, etc. in a gram mole of any chemical substance. Of course if we used some other mass unit for the mole such as "pound mole", the "number" would be different than 6.022 x 1023.
852232
Pv = nRT\nn = m/M (M Molecular weight)\nPV = (m/M)RT\nP = (m/V)RT/M\nPM/RT = m/v = Density.\nPlug the numbers, watch the units and get the density.\n\nOh a numerical answer, yes, ...42.
773122
n(H2O) = m/M = 8.02 / 18.02 = 0.4451 mols\n\nno. of molecules = n(H2O) x Avogadro's Number = 0.4451 x (6.02 x 10^23) = 2.68 x 10^23\n\n1 molecule of H20 = 2 atoms of H and 1 atom of 0\n\nno. of atoms of H = 2 x no. of molecules of H2O = 2 x (2.68 x 10^23) = 5.36 x 10^23
924166
yes u can. use the equation E = hf where E is the energy and h is the planck constant. once u find f which is the frequecy...insert into equation velocity = wavelength x frequency...assuming u noe the velocity of the hydrogen!! :)\nOH but by the way since ur answer is in kj/mol u need to convert it to kj with the avogadro number which i forget...i'm sure u can find out!
744373
For the first one, multiple the number of moles by the molecular mass of Helium.  Helium is mono-atomic (one atom per molecule) so the atomic mass of Helium is used:\n\n4.56 moles * 4.003 g/mol = ? (you can at least do the math)\n\nFor the second part, each mole of pure substance contains Avogadro's number of molecules (or atoms for an element).\n\nThe number of moles of Zinc is the mass divided by the atomic mass (also called the atomic weight).  For Zinc this is 65.38 g/mol:\n\n12 g / 65.38 g/mol = number of moles of Zinc.\n\nEach mole contains 6.022 * 10^23 atoms of Zinc, so just multiple the number of mole above by 6.022 * 10^23 atoms/mole to get your answer.
291328
In chemistry, balancing certain equations right can give you coefficients in the form 1+1=3, but that has to do with Avogadro's number.
670103
Assuming that NO2 is an ideal gas is these conditions (which is a reasonable assumption at such a low P), the number of moles into that flask is: n = PV/(RT) where P = 432 mmHg = 0.568 atm, V = 0.5 L, T = 60 C = 333 K, R = 0.082 L atm/(mol K).\nThen: n = 0.01 mol and, taking into account the Avogadro Number (in number of particles/mol) the number of molecules is NM = 0.01*6.022x10^23 = 6.022x10^21.
782235
Avagardro's Number = one mole, and all of the masses on the periodic table are in grams/mole.One mole of P equals 30.97g, so d. (c is the only other logical answer, but O2 has a molar mass of 32g/mole beacuse 1 oxygen has a molar mass of 16)\n\nGet used to moles, you'll see them all throughout chemistry.
750574
3.01E23 atoms of tin is about one-half mole (one mole is Avogadro's number -- 6.023E23 -- of anything).  So, which of the numbers you give is roughly one-half of the atomic weight of tin -- 118.69 grams/mole?
722679
60\n\nThe Babylonian sexagesimal number system, all Pythagorean triples have the property that the product of the 3 sides is a multiple of 60. I lived at a house which was no 60 in its street. And I am now 60.
980378
The correct answer is 12+22+11 = 45.  This is assuming that you actually meant "molecule".  If you really meant "mole", then the lone dissenter is partially correct.  Avogadro's number, 6.023 x 10^23, is the number of molecules in a mole of *anything*.  Therefore, the number of atoms in a *mole* of sucrose would be 45 x 6.023 x 10^23 (sorry, I don't have my calculator handy).
813106
Just an initial note: NH3 is ammonia\n\nA. \nInitial math:\nSince you have 8.5 grams of NH3, you have to convert grams mols, then into molecules. \nSo you do: 8.5 grams of NH3 / 17 grams in 1 mole of NH3 and X 6.022 x 10^23 molecules in one mole\nYou get 3.011 x 10 23 molecules, and from that you subtract 1.5 x 10^23 molecules, and you get: \n<b>1.511 x 10^23</b>\n\nB. Then, you convert 1.5 x 10^23 to moles by dividing by 6.022 x 10^23 moles, which equals .249 moles of NH3. \nThen you convert 8.5 grams of NH3 to moles too by dividing 17 grams of NH3 per mole again, and get: .5 moles! \nso: .5 mol - .249 mol = <b>.241 mol</b>\n\nC. \nFrom before, you know 1.5 x 10^23 molecules of NH3 is .249 moles. You convert this to grams by multiplying .249 by 17 grams per mol and get: 4.233 grams. \nSo: 8.5 grams - 4.233 grams = <b>4.267 grams</b>\n\nD. From before, you know you have .241 moles of ammonia left. So, you multiply this by avocado's number (6.022 x 10^23) and get: 1.45 x 10^23 molecules of ammonia. Then, you can see that there are 3 atoms of hydrogen of per molecule of ammonia, and multiply the number of molecules by 3 and get: \n<b> 4.354 x 10^23</b> \n\nI think those should be right. Sorry about the sig figs though!
616769
9.109 3826(16) × 10−31 kg (Kilograms)\n1⁄1836.152 672 61(85) amu  (Atomic mass units) \n0.510 998 918(44) MeV/c2 (Mega electonvolts/coloumb squared)
96063
It's AvOgadro :-)\nThe number is 6.0221415...x10exp23 (that is, followed by 23 zeroes).\nThis valuable number represents the number of atoms, molecules, etc. in a gram mole of any chemical substance.\nAvogadro (he had a really long name) proposed in 1811 that equal volumes of gases, at the same temperature and pressure, contain equal numbers of molecules. More about this story in the second link.
762286
I agree with Keith P.\n\nYou solve this by finding the number of moles of Sn and F.  You divide the sample (g) by the formula weight of the element.\n1.0g/118.71g = 0.0084\n0.640g/ 19g = 0.0336\n\nNext you divide the smaller of the two by the other to establish a sort of ratio.\n0.0336>0.0084\n\n0.0336/0.0084 = 4\nThus there is one atom of Sn for every 4 atoms of F and the empirical formula is SnF4.
174643
The formula in the above answer is incorrect since it omits the aromatic ring and the 9 subsequent repeating units (it's not 9 repeating -OH groups, that makes no sense).\n\nThe empirical formula by my calculations seems to be: C33 H60 O10
1062179
well, lets think about this\n\navagodro's number is the number of atoms in a mole and =\n6.02 x 10^23\n\nso, if we divide the number of atoms in the problem by the number of atoms in a mole, we will get moles of the atom\n\nI think you get .0027 moles.\na quick glance at the periodic table of the elements will give you the molecular weight for silicon\n28.0855 grams/mole\n\nmultiply and you get .076 or in sci notation, 7.6 x 10^-2\n\nassuming I punched the calculator correctly, it looks like "E".