The amount of oxygen required to burn completely 570 g of octane is

$\left[2{\mathrm{C}}_8{\mathrm{H}}_{18}+25{\mathrm{O}}_2\to 16{\mathrm{CO}}_2+18{\mathrm{H}}_2\mathrm{O}\right]$

$\left[2{\mathrm{C}}_8{\mathrm{H}}_{18}+25{\mathrm{O}}_2\to 16{\mathrm{CO}}_2+18{\mathrm{H}}_2\mathrm{O}\right]$

2 moles octane = 25 moles ${\mathrm{O}}_2$

$2\times 114\mathrm{g}=25\times 32\mathrm{g}$

570g......?

$\frac{570}{2\times 114}\times 25\times 32$

= 2000g

2000gr of Oxygen is required to completely burning of 570gr of Ocane