If the heat of combustion of 1-butanol (C4H9OH) is 2,710 kJ/mol, what mass of oxygen is consumed when enough 1-butanol is burned to yield 26,400 kJ of energy?

Question

I have no clue where to begin I thought to use enthalpy but it didnt work

Answer 1

C4H10O + 6O2 ==> 4CO2 + 5H2O

Burning 1 mol butanol uses 5 mols O2 (5*32 = 160 grams O2). How many grams O2 will be needed to release 26,400 kJ? That's 160 g O2 x (26,400 kJ/2,710 kJ) = ?

Answer 2

Isn't it 6 mol of o2