the mass of 2 moles of oxygen atoms (atomic mass 16) is...?
957979
64 g \nOxygen is diatomic. So molecular weight = 16*2 =32.\nTherefore mass of 2 moles = 64g.
384930
Formula mass is the mass of one mole of material molecule; while atomic mass is the mass of one mole of a single atom. e.g. the atomic mass of hydrogen (H) is 1, while its molecular mass is 2 since the molecule has two hydrogen atoms (H-H or H2)
86157
"water has the molecular formula H2O, indicating that there are two atoms of hydrogen and one atom of oxygen in a molecule of water. Rounded to three decimal places, the atomic weight of hydrogen is 1.008 amu and that of oxygen is 15.999 amu. The molecular weight of water is thus (2×1.008)+(1×15.999)=2.016+15.999=18.015 amu. Since atomic weights are average values, molecular weights are also average values. On the average, a molecule of ordinary water weighs 18.015 amu."
70597
Three -- two atoms of hydrogen (H2), and one of oxygen...\n\nH2O
995159
Use the atomic weights of the individual elements, and add them together.  For instance, if I had water, H2O:\n\nH - 1.01 g * 2 = 2.02 g\nO - 16.00 g\n\nSo the molar mass of H2O would be 18.02 g/mol.\n\nIf I wanted to convert from grams to moles, I would divide the grams by the molar mass.  Grams cancels out to be left with moles.\n\nIf I wanted to convert from moles to grams, I would multiply the moles times the molar mass.  Moles would then cancel out to be left with grams.
769142
Easy: the molecular mass of a water molecule has 2 hydrogen atoms and 1 oxygen whereas a normal parcel of air is mostly oxygen and nitrogen.\n\nMoist air will be lighter at 18 and 28.98 for dry air.
852876
Assuming STP, one mol of oxygen (64 grams) would be 22.4 L.\n\nSo divide 1 by 22.4 and that's how many mols you have. Multiply by 64 grams and there's your mass of one Liter. It'd be useful to convert to kg now, just multiply by 10^(-3)\n\nWeight is mass multiplied by the acceleration of gravity. Assuming this is on earth, acceleration is 9.8.\n\nSo final answer should be 28*10^(-3)  kgm/s^2==>.028 Newtons\n\nIf you want pounds, multiply by 0.2248 to get 0.0062944\n\nShould be right, although I'm not sure. I'm mixing physics and chemistry...unless you wanted mass, not weight, then ignore everything after mass.\n\nEDIT: Just wanted to point out a mistake in the answer above...he forgot that oxygen gas is O2. Weight of one mol of O is 32 g, but molecular weight of one mol of O2 is 64 g.\n\n2nd EDIT: Just realized...I was wrong, Maussy right. Atomic weight of oxygen is 16, so molecular weight of O2 is 32 g. I didn't even look at a periodic table; I was thinking of sulfur. Sorry for any confusion.
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.
872375
1) determine the mass of carbon, hydrogen and oxygen.\ncarbon: 7.793 g x (12 / 44) = 2.125 g\nhydrogen: 3.190 g x (2 / 18) = 0.354 g\noxygen: 3.192 - 2.125 - .354 = 0.713 g\n\n2) convert to moles.\ncarbon: 2.125 / 12 = 0.177 mol\nhydrogen: 0.354 / 1 = 0.354 mol\noxygen: 0.713 / 16 = 0.0446 mol\n\n3) divide each molar amount by the lowest value to obtain small integers\ncarbon: 0.177 / 0.0446 = 4\nhydrogen: 0.354  / 0.0446 = 8\noxygen: 0.0446 / 0.0446 = 1\n\nThe empirical formula of the substance is (C4H8O)n\nThe atomic masses add up to 72.1 g, which is also the molar mass of the compound. Therefore n=1 and we find C4H8O
952814
That would be correct if you were looking for the total mass of oxygen but you're not.  You're looking for sulfur.  You know the molecular weight of sulfur and you know the number of moles you need.  I'm not going to do it for you.
518927
(46.2 grams)/(32 grams per mole) = 1.44 moles of Oxygen (O2)
457002
That may be right, but the website just says that its 7 X 10^27-it doesnt explain how they figured it..\n\nSo lets see if we can figure how they got that number: There are 6 X 10^23 atoms per mole.  Lets say the average atom (most being hydrogen-1, followed by oxygen-16, and carbon-12) has a molar weight of 7.  So, 6 X 10^23 average atoms in the body would weigh 7 grams.  To get 70 kilograms, we have to multiply that by 10,000.  So, 2000 times 6 X 10^23 gets us about 6 X 10^27.  That's pretty close to 7 X 10^27.  I have a feeling that the real average molar weight per atom would be quite a bit smaller than 7, though.
751855
The first step is to balance the equation first, which yields\n\n2SO2 + O2 ---> 2SO3\n\nNow, find the total number of moles of 160 g O2:\n\n# of mole = 160/(16*2)\n= 5 moles.\n\nAccording to the balanced equation, the mole ratio between SO2 and O2 is 2:1. In other words, it takes twice amount (in moles) of SO2 to react with 1 unit of O2.\n\nSince we react 5 moles of O2, we need 10 moles of SO2.\n\nMass of SO2 = # mole * molecular weight\n= 10 * (32 + 16*2)\n= 640 g of SO2 is needed.
956489
2 SO2 + O2 --> 2 SO3\n\n\nok, 64.00 g oxygen times the molar mass of 02( 32.00) to get mols of O2 then time the mole ratio of O2 to SO2 which is (2 mol SO2/2 Mol O2) and then u have the mols of SO2 times that by the molar mass of SO2 to get the mass of SO2\n\n64.00 x 32.00 x 2/2 x molar mass of SO2
840490
One way to count atoms is by using the molar unit.\nSince different atoms have different weights (masses) the molar quantity of different elements will have different weights.  However, the molar quantity will have the same number of atoms - 6∙02 x 10^23.  This number value is known as Avogadro Constant.\n\nExamples:\n Hydrogen: 1 mole = 1g and contains 6∙02 x 10^23 atoms.\n Oxygen : 1 mole = 16g and contains 6∙02 x 10^23 atoms.\n Water :  1 mole = 18g and contains 6∙02 x 10^23 molecules.
95148
Actually, the mass of a proton is 1.00727664669 atomic mass units.\n\nAn atomic mass unit is defined such that Carbon 12 is exactly 12.  The carbon atom weighs less than 12 times the proton (because of nuclear binding energy).
895124
The data from the elemental analysis is used to calculate the empirical formula which would be C3H6O.  I am assuming you can get to that point; if not check your gen chem text or ask another question.  \n\nThe gas data is used to determine the molar mass.  First calculate the moles of gas using the ideal gas law.  The value you will calculate is 0.0602 mol.  Molar mass is 6.97 g / 0.0602 mol = 116 g/mol.  \n\nThe empirical formula, C3H6O would have a molar mass of 58 g/mol.  Since the molar mass of the molecular formula is 116, twice that of the empirical formula, the molecular formula would be C6H12O2.