If 6.50 g of the unknown compound contained 0.217 mol of C and 0.433 of H, how many moles of oxygen,O, were in the sample?

Answer 1

g C = 0.217 mol C x atomic mass C
g H = 0.436 mol?(no unit) x atomic mass H
gC + gO + gH = 6.50 g.

Answer 2

0.216 mole