posted by kenny on .
A 0.6996 g sample of a compound containing C, H, and F was burned to produce 0.6039 g CO2 and 0.1235 g H2O. If the molar mass of the compound was determined to be approximately 102.0 g/mol, what is its molecular formula?
.6996g of sample at 102g/mol = 0.006859 mol
.6039g CO2 at 44g/mol = 0.1373 mol of C
.1235g H2O at 18g/mol = 0.006859 mol of H
so, each mole of the compound produces 2 moles of H and 2 moles of C
The formula is C2H2F?
C2H2 has mass 26
102-26 = 76
Fluorine has mass 19
76/19 = 4
The compound has formula C2H2F4