empirical formula?

Question

determine empirical formula from 3.37 g silicon combined with 12.4 g chlorine

Answer 1

Well, Kitty and sourceof are right, but their answers may not be clear enough for you.

You probably know that you find the number of moles by dividing the grams (3.37 and 12.4) by the atomic weights (not atomic numbers).

But after you get the number of moles and divide the larger number by the smaller one, you might get an answer like 1.487.

So don't turn in an answer like Ni1.487 P (if you were working with Ni and P, instead of Si and Cl).

Instead, note that 1.487, if you round it slightly (for rounding error), you get 1.5. And you can turn 1.5 into an integer if you double it (to get 3 Ni atoms). But you ALSO have to double the number of P atoms (in this example). So your answer is that Si3P2 is the empirical formula.

And I assume you know that "empirical formula" means that there really aren't any Si3P2 molecules, but the RATIO of Si atoms to P atoms in the compound is 3 to 2. Similarly, there is no NaCl molecule, but it has been discovered EMPIRICALLY (i.e., by real-world experiment) that table salt has equal numbers of Na and Cl atoms, so NaCl is the formula we use for it.

Hope this helps.

Answer 2

convert your grams into moles by dividing each weight by proper molecular weight for each element then divid each value you got by the smallest mole value so one of them will be 1 and the other will be correct number more than 1 and that will give you your empirical formula

Answer 3

convert both grams to moles, divide by the lowest amount, and they combine in that ratio.