help with balancing

[smaxton]

what i one way to balance 2C₈ H₁₈ + O₂ = CO + H₂O

[KriggY]

its
2C₈H₁₈ + 17O₂ = 16CO + 18H₂O
another option is:
2C₈H₁₈ + 25O₂ = 16CO₂ + 18H₂O

[smaxton]

cheers

[GrahamKemp]

Step by step.

(1) Partial Oxidation (produces carbon monoxide)
x C8H18 + y O2 = z CO + w H2O

Balance C: z = 8x.
Balance H: 2w = 18x, or w = 9x.

x C8H18 + y O2 = 8x CO + 9x H2O

Balance O: 2y = 8x + 9x, or 2y = 17x.
Lowest Integer Solution: y = 17, x = 2

2 C8H18 + 17 O2 = 16 CO + 18 H2O


(2) Complete Oxidation (produces carbon dioxide)
You just need an extra 16 O (as 8 O2) to produce 16 CO2 instead of 16 CO.

2 C8H18 + 25 O2 = 16 CO2 + 18 H2O