 percent comp part 2 by eshamblin on 07-13-2018
 H is 1.01 grams per mole O is 16.00 grams per mole  OK, lets take water, or H20 as an example. First, find the molar mass of water by adding up the atomic masses of the elements. Thats easy. You can use your handy pocket-sized laminated periodic table.    Oh, I get it. their mass numbers.    molar mass = (2 x 1.01) + 16.00 molar mass = 18.02  Get the molar mass by tallying all the masses of elements in the compound. You have to look at the subscripts and note that after the hydrogen (H), the 2 indicates there are two atoms of hydrogen. There arent any subscripts after oxygen (O), which means only one atom needs to be counted.    I'm still with ya...    mass % H = (2 x 1.01) / 18.02 x 100% mass % H = 11.19% mass % O = 16.00 / 18.02 mass % O = 88.81%  Now, divide the mass of each element by the total mass to get the mass percentages:    Looks like the answer is up there in the sky!    vote:     | login to vote | log in to flag this comic as inappropriate
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