Answer
Approximately 35.0877 grams.
Work Step by Step
The proportion is:
25 mols $O_2$ for 2 mol $C_8H_{18}$.
25 mols $O_2$ in grams: 25*(16*2) = 800g.
2 mol $C_8H_{18}$ in grams: 2*(8*12+18*1) = 228g.
800g of $O_2$ for 228g of $C_8H_{18}$:
$\frac{800}{x} = \frac{228}{10}$
228x = 800*10
228x = 8000
x = $\frac{8000}{228}$
x $\approx$ 35.0877
