i have the answer i just dont know how to get it?
2006-10-02 18:12:13 · 3 answers · asked by tx_guy505 1 in Science & Mathematics ➔ Chemistry
A mole of any substance is it's molecular weight in grams.
3.175 mol(O2) = 3.175*31.9988
2006-10-02 18:16:50 · answer #1 · answered by Helmut 7 · 1⤊ 0⤋
the molecular mass is the amount of mass (g) in one mole (mol) of a given substance. the amu means atomic mass units, which is the mass of one molecule. any time you see amu's as units, you can assume that the amount of 1 mole of that molecule would weigh that many grams.
so, since the molecular mass of O2 is 31.9988 amu, then 1 mole of O2 would weigh 31.9988 g, or you could also say O2 weighs 31.9988 grams per mole (g/mol).
since you want to find the mass of 3.175 moles of O2 instead of 1, just multiply the molecular mass by the # of moles.
(3.175 mol O2) x (31.9988 g/mol O2) = 101.59619 g O2
= 101.6 g O2
(remember since the number with the least digits is 3.175, you have to round up to 4 significant figures).
2006-10-03 01:50:44 · answer #2 · answered by johnny m 2 · 2⤊ 0⤋
Just multiply the number of mols by the molecular mass.
3.175 x 31.9988 =
The resulting mass units are taken to be grams in this case.
Engineers sometimes use other units, such as the kilogram-mol
or the pound-mol.
2006-10-03 01:21:32 · answer #3 · answered by hls 6 · 1⤊ 0⤋