a. 150.0g Fe2O3
b. 10.0mg No2
c. 1.0 femtomoles of NO2
d. 1.5 x 10^16 molecules of BF3
e. 2.6 mg BF3
please tell what conversion factors used. thank you.
2006-11-22 10:47:23 · 2 answers · asked by j a 1 in Science & Mathematics ➔ Chemistry
I'll show you how to do one; then you'll know how to do the rest:
a. On the periodic table, find the atomic weight for both Fe and O.
Fe = 55.845, O = 15.9994
Multiply by the number of atoms of each in each molecule of Fe2O3 to get the molecular mass (the mass, in grams, of one mole of the compound) of Fe2O3:
2(55.845) + 3(15.9994) = 159.6882
Divide 150 by this number to get the number of moles:
150/159.6882 = 0.939 moles
2006-11-22 10:53:02 · answer #1 · answered by bgdddymtty 3 · 1⤊ 0⤋
no coversions needed
Fe has 203 moles
No has 2
femtomoles i think is 5 so that is 10
d. 1,500,000,000,000,000,000
e. 3
2006-11-22 18:51:55 · answer #2 · answered by chowda99@sbcglobal.net 3 · 0⤊ 3⤋