Your car burns mostly octane, c8h18, as a fuel. how many liters of oxygen are needed to burn a kilogram of octane

2.5 litres

Explanation:

First, let us write the balanced chemical reaction of the reaction going on in the internal combustion engine. The balanced equation is given in the reaction below;

2 C8H18 + 25 O2 > 16CO2 + 18 H2O. (1).

OR

C8H18 + 12.5 O2 >8CO2 + 9 H2O. (2).

From the equation of reaction above, we can see that one mole of C8H18 reacts with 12.5 moles of O2 to give 9 moles of water and 8 moles of Carbondioxide, CO2.

Hence, in one Kilogram, that is 1000 grams, we are to calculate how many liters of oxygen are needed.

So, the molar mass of C8H18 is 114 grams per mole(that is; 12×8 + 1×18).

We have to calculate the number of moles using the formula below;

Number of moles,n= mass/molar mass.(3).

Number of moles,n= 1000 gram/ 114 gram per mol.

Number of moles,n= 8.8 moles.

Thus, 12.5 moles of oxygen reacting and the number of moles of oxygen needed is (12.5 × 8.8 ) moles = 110 moles.

The volume of litres of oxygen needed= 110 moles × 22.4 dm^3.

===> 2464 dm^3.

==> 2.5 litres of oxygen is needed.