A natural product has the molecular formula C23H27O7.
How many oxygen atoms are in 2.92 picograms of this compound?
2007-09-30 10:24:03 · 1 answers · asked by Anonymous in Science & Mathematics ➔ Chemistry
This substance has a molecular weight of:
23(12.011)+27(1.008)+7(15.999) = 185.462
Therefore, 6.022*10^23 molecules have a mass of 185.462 grams. Divide 2.92 picograms by this gram molecular weight to determine how many moles you have.
2.92*10^-12 g / (185.462 g/mole) = 15.744*10^-15 moles
Then multiply the number of moles by the number of molecules in a mole to determine how many molecules you have.
(15.744*10^-15 moles) * (6.022*10^23 molecules/mole) = 94.81 * 10^8 molecules
Multiply that by the number of oxygen atoms in a single molecule, and get:
7*(94.81*10^8) = 663.673*10^8
or
6.64*10^10 oxygen atoms
2007-09-30 11:02:24 · answer #1 · answered by skeptik 7 · 0⤊ 0⤋