what amount(moles)are represented by each of these samples? a.150.0g Fesmall 2 O small 3 b. 10.0mg NOsmall 2 c

Answer 1

For Fe2O3:

1 mole of Fe2O3 weighs [(2 x 55.85) + (3 x 16)] = 159.7g

So: 150g/159.7g/mol = 0.939 moles.

For NO2 it is done the same way:

1 mole NO2 = 14.0 +(2 x 16) = 46g/mole

10mg = 0.0100g:

0.0100g/46g/mol = 0.000217mol

Answer 2

Using a periodic table, add 2 times the atomic mass of iron to three times the atomic mass of oxygen. Take the resulting answer, and divide 150.0 by it.

Then do the same with one times nitrogen and two times oxygen.