Someone please help me I beg you please!!!!!!!!!

The combustion of octane, C8H18 proceeds according to the reaction.

2C8H18 (I) + 25O2(g) ----> 16CO2(g) + 18H2O(I)
if 354 mol of octane combusts, what volume of carbon dioxide is produced at 18.0 degrees celsius and 0.995arm?

according to reaction :

2 moles of C8H18 gives 16 moles of CO2

so 1 mole of C8H18 will give 16/2 = 8 mole of CO2

so 354 mole of C8H18 will give 354 X 8 = 2832 mole of CO2

now using PV = nRT to calculate volume of CO2

P = 0.995 atm
V = ? L
n = 2832
R = 0.0821 L atm/K/mole
T = 18+273 = 291 K

0.995 X V = 2832 X 0.0821 X 291

V = 67659.595/0.995 = 67999.593 L

feel free to ask any questions