Asked by Jamie Marie

How would you find the empirical formula for this... a substance was found by analysis to contain 20% by mass calcium and 80% by mass bromine.


Would it be CaBr2?

This is what I did...

50g Ca * 20 mol Ca/801.56g Ca = .499 mol Ca

80g Br * 80 mol Br/6392.32g Br = 1.001 mol Br

1.001/.499 = 2 so CaBr2

Answers

Answered by DrBob222
Yes, the answer is CaBr2 but I don't buy the way you obtained that formula. Did you just pull 50 g Ca and 80 g Br out of thin air? The proper way to work it is the way I showed you in your first post.
Answered by Manas
First we find the moles of each assuming that mixture is having total mass of 100 grams. So mass of Ca = 20 g and Br =80

Moles of Ca = 20 g/40.08 (g/mole)= 0.499 Mole

Moles of Br = 80 g/ 1.001 moles

So now we can find the molar ratio = 0.499/1.001 =1/2
That means Ca1Br2 so the empirical formula would be CaBr2.
This is absolutely right.
There are no AI answers yet. The ability to request AI answers is coming soon!

Related Questions