Question

1. The octane present in gasoline burns according to the following equation:

2 C8H18 + 25 O2 → 16 CO2 + 18 H2O

(a) How many moles of O2 are needed to react fully with 27.5 moles of octane?

Answer 1

To react fully with 27.5 moles of octane, you would need 343.75 moles of O2.

Step-by-step explanation:

In order to determine the number of moles of O2 needed to react fully with 27.5 moles of octane, we can use the balanced chemical equation:

2 C8H18 + 25 O2 → 16 CO2 + 18 H2O

From the equation, we can see that for every 2 moles of octane, we need 25 moles of O2. Thus, for 27.5 moles of octane, we would need:

(27.5 moles octane) * (25 moles O2/2 moles octane) = 343.75 moles of O2

Answer 2

`n_(O_2)=343.75molO_2`

Step-by-step explanation:

Hello there!

In this case, according to the combustion of octane:

`2C_8H_1_8+25O_2\rightarrow 16CO_2+18H_2O`

We can see there is a 2:25 mole ratio of octane to oxygen; therefore, we can calculate the moles of oxygen via the following stoichiometric factor:

`n_(O_2)=27.5molC_8H_1_8*(25molO_2)/(2molC_8H_1_8) \\\\n_(O_2)=343.75molO_2`

Best regards!