<u>Given:</u>
Mass of the unknown compound (believed to be Sarin) = 10.0 g
Mass of CO2 produced = 15.6 g
Mass of H2O produced = 6.4 g
<u>To determine:</u>
If the unknown compound is Sarin
<u>Explanation:</u>
The molecular formula for Sarin is: C₄H₁₀FO₂P
Based on stoichiometry the C:H ratio = 4:10 i.e 2:5
Now, from the combustion data:
# moles of CO2 produced = # moles of C present in the unknown sample
Similarly, (# moles of H2O produced)*2 = # moles of H present in the unknown sample
# moles of CO2 = 15.6 g/44 g.mol-1 = 0.354 moles
# moles of H2O = (6.4 g/ 18 g.mol-1 )* 2 = 0.711 moles
The C:H ratio = 0.354 : 0.711 = 1:2
Ans: Since the C:H ratio does not match the actual stoichiometry based on the molecular formula, the unknown compound is not Sarin.
