Question

Using the following equation for the combustion of octane, calculate the amount of moles of carbon dioxide formed from 100.0 g of octane. The molar mass of octane is 114.33 g/mole. The molar mass of carbon dioxide is 44.0095 g/mole. 2 C8H18 + 25 O2 → 16 CO2 + 18 H2O ΔH°rxn = -11018 kJ

Answer 1

We are given the chemical reaction and the amount of fuel used for the process. We use these data together with the molar masses to obtain what is asked. We do as as follows:

100 g C8H18 ( 1 / 114.33) ( 16 / 2 ) = 6.9973 mol CO2 produced

Answer 2

Answer : The amount of moles of carbon dioxide formed will be, 6.96 moles.

Solution : Given,

Mass of octane = 100 g

Molar mass of octane = 114.33 g/mole

Molar mass of carbon dioxide = 44.0095 g/mole

First we have to calculate the moles of octane.

$\text{Moles of octane}=\frac{\text{Mass of octane}}{\text{Molar mass of octane}}=\frac{100g}{114.33g/mole}=0.87mole$

Now we have to calculate the moles of carbon dioxide.

The balanced chemical reaction is,

$2C_8H_{18}+25O_2\rightarrow 16CO_2+18H_2O$

From the balanced chemical reaction, we conclude that

As, 2 moles of octane react to gives 16 moles of carbon dioxide

So, 0.87 mole of octane react to gives $\frac{16}{2}\times 0.87=6.96$ moles of carbon dioxide.

Therefore, the amount of moles of carbon dioxide formed will be, 6.96 moles.