[Natsuko]

Note: I'm not asking for the answer. In fact, if someone does find out the answer it would be best not to tell me. I'm just confused as to the steps I should take to FIND the answer.




Superman returned from the new planet Fra( I ) Con with an unusual sample of rock ( NOT Kryptonite ). His X-ray vision revealed the Following: 0.15 m + 0.02 m by 0.4dm + 0.1dm by 63.0 mm +8.0 mm: 0.777 kg + 0.333 kg ; 22.075% calcium, 20.529 % iron, 26.490 % carbon and the remainder nitrogen. It is 1630.8 g/mole.

While cutting up the sample with a laser, Lois lane slipped on water on the floor and the pieces of rock turned out irregular rather than regular. Lex luthor wondered what the MINUMUM # of atoms int he following piece --therefore: displacement of water revealed.

V(initial) = 36.2 mL, V(final) = 51.9 mL where the graduated cylinder has an error of +2.4mL.






So....So far I know that I should calculate the imperical formula from % using molar mass- looking for molecules, but other than that I'm seriously lost.

This is a lengthly problem, but help would be much appreciated.

[Yggdrasil]

In one mole, you have 1630.8g of substance.  How many grams of calcium do you have in one mole of your substance?  How many moles of calcium per mole of substance?  Repeat for the rest of the elements to get the molecular formula.