Is this done right?

White phosphorous, P4, spontaneously bursts into flame in Oxygen gas. if 6.5 g of white phosphorous reacts completely with oxygen to form 11.54g of a phosphorous oxide, what is the empirical formula of this oxide?

this is what i did:

total = 11.4 g , P4 = 6.5 g , therefore O2= 5.04 g

converted P4 and O2 to moles and divided by the smallest # of moles (which was moles of P4= 0.0525)

so the empirical formula would be PO3

however this isn't one of the options for the answers :S

did i do smthg wrong?

thanks for help in advance!

7 answers

Yes, you calculated mols P4 and not P. Also, you subtracted wrong; 11.4-6.5 = 4.90
6.5/31 =about 0.2
4.90/16 = about 0.3
ratio is P1:O1.5 or P2O3 for the empirical formula.

sorry it was a typo, 11.54.

but still , you are right. 5.04 / 16 = 0.315 so answer ended up being the same in the end.

thank you !

You're welcome.

I dislike chemistry sometimes.

YUP RIGHT

yup hahaha

awda