How many moles of aspirin are in a tablet weighing .301 g

You need to look, not at the mass of the tablet, but at how much aspirin is in a tablet because much of the tablet is filler, usually starch, or some other inert material.

Full strength aspirin tablets contain about 325 mg, while low dose aspirin tablets contain 81 mg.

So I am not sure where 0.301 grams comes from, since the mass of a tablet is a gram or two.

0.301 g aspirin x (1mol aspirin / 180.157 g) = 0.00167 mol aspirin

0.001671 mol aspirin x (8 mol H / 1 mol aspirin) x (6.022 x 10^23 atoms / 1 mol H) = 8.05x10^21 atoms H

========== Follow up ==========

Brown Cow has a ridiculously large number of moles in a small amount of aspirin.

''. so there r 54.22 moles in .301 gram''

No way.

First we find the molar mass. (12.01*9) (1.008*8) (16.00*4) = 180.154

Then check out pisgahchemist is answer. He corrected my answer. Thank moo!

Atoms = moles x 6.022 x 10^23 (Avogadro is number).

for moles:

mol C9H804 = 0.301 g x 1 mol C9H804 = 0.00167 mol C9H8O4
----------------------
................ 180.17 g C9H804

hydrogen atoms:

atoms H = 0.00167 mol C9H8O4 x 8 mol H x 6.022e23 atoms H =
----------- -------------------------
....................1 mol C9H8O4.....1 mol H

[do the calculator work yourself]
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