A sample of CH2F2 with a mass of 19g contains _________ atoms of F

Question

CH2F2= 52.03
x = grams of F

x/19 = 38/52.03
x= 13.88 grams

13.88/38 = 0.365 moles
0.365*6.02x10^23 = 2.2x10^23
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But it tells me that that answer is wrong so what did I not do correctly, and what does that make the answer?

Answer 1

What proportion of the molecule is F?

2*19/(12+2+2(19))=38/52 rounded atomic numbers.
so F is 13 grams (about) as you did.

Now , that is how many moles of F?

13/19=.7 (about moles)
see your error?

Answer 2

Ah, Thanks!