50.0 g of sulfur is mixed whit 100.0 g of iron and the mixture is heated. when the reaction is completed, 12.7 g of iron remains. what is the empirical formula of the compound formed?
2007-01-15 14:09:16 · 2 answers · asked by Anonymous in Science & Mathematics ➔ Chemistry
The iron and sulfur will react in molar ratios, so we need to calculate the moles involved.
50.0 g of sulfur / 32 g per mole = 1.56 moles
100.0-12.7 = 87.3 g of iron used / 55.8 g per mole = 1.56 moles
The ratio is 1:1, so the formula is FeS
2007-01-15 14:40:42 · answer #1 · answered by reb1240 7 · 0⤊ 0⤋
i dont have time to answer it exactly and directly right now, because i have to study for a chemistry final, but here are the basic rules for finding the EF of something.
1. write out the formula
2. find the number of moles of each product and reactant
3. divide all the answers by the answer with the smallest value
4. then make the numbers whole. for example, if one is 1.01 moles of Fe, make it 1 but, if it is 1.4 or something higher, figure out what you need to multiply that by to make it close to a whole number, i.e 2 and Fe would be 3
here's a little rhyme to remember.
percent to mass
mass to mole
divide by smallest
then make whole
i'll try and get you a better explanation and an answer in the next few days. i'm just a little swamped right now. sorry
2007-01-15 22:38:20 · answer #2 · answered by audrey 2 · 0⤊ 0⤋