Answer to Question #18776 in Chemistry for Laveeza

Question

octane burns completely in oxygen according to the equation
2C8H18 + 25O2 = 16CO2 =18H20
[a) calculate the volume of oxygen i.e. needed for the comp. combustion of 1 dm3 of octane vapor
b) what mass of water vapor will be formed

Answer 1

V(C₈H₁₈): V(O₂) = 2 : 25
V(O₂) = 1 dm³ * 25/2 = 12.5 dm³
m = n * M;
n = V/ Vm
n(C₈H₁₈) = 1dm³/22.4 dm³/mol = 0.0446 mol;
n(H₂O) = 0.0446mol *18/2 = 0.4 mol
m(H₂O) = 0.4 mol * 18 g/mol = 7.22 g