A 24.3g sample of a compoud XO2 contains 3.365 x 10^23 oxygen atoms. Determine the molar mass in g/mol of the element X. Show your work.
3.365*10^23 / 6.023*10^23 = 0.559 moles
O2 has mass 32, so .559 moles O2 has mass 17.878g
That leaves 6.422g of X
Since we have .559 moles of X, that makes its mass 11.488g/mole
Hmmm. Not sure what element X would be. Better double check my work...