We are attempting to bum 85 gs of ndecade C10H22 in 3500 gs

We are attempting to bum 85 g/s of n-decade (C_10H_22) in 3500 g/s of air (21percentage O_2, 79percentage N_2). Determine whether or not this mixture will actually bum (is flammable)

Solution

In order to have complete combustion 15 mols of air requires for 1 mole of fuel.

here we have 41 g/s or 0.041 kg/s air per 1 g/s or 0.001kg/s fuel

Ratio of A/F is 41:1,

1kmol C10H22 = 10(12)+22(1) kg = 142 kg
1kmol air = 2(16)+3.76 x 2x(14) = 137.28 kg

a(C10H22) + 10(O2 + 3.76 N2) 10(CO2) + 11(H2O) +10(3.76 N2)

Now, 10 kmol air is requires for each kmol of C10H22,

10 (137.28)/142=15:1

9.66.1=15.1

Mixture will burn, but not stoichiometrically