Answer: The equation for combustion of octane is given below. The mass of octane needed is 49.87 g.
Explanation:
Combustion reaction is a type of reaction in which a hydrocarbon in the presence of air (oxygen) decomposes into carbon dioxide and water.
Chemical equation for the combustion of octane is given by:
[tex]2C_8H_{18}+25O_2\rightarrow 16CO_2+18H_2O[/tex]
As, oxygen is taken in excess. Therefore, octane is considered as limiting reagent because it limits the formation of product.
By Stoichiometry,
16 moles of carbon dioxide is produced by 2 moles of octane.
So, 3.5 moles of carbon dioxide is produced by = [tex]\frac{2}{16}\times 3.5=0.4375moles[/tex] of octane.
To calculate the mass of octane needed, we use the formula:
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}[/tex]
Molar mass of octane = 114 g/mol
Number of moles of octane = 0.4375
Putting values in above equation, we get:
[tex]0.4375mol=\frac{\text{Given mass}}{114g/mol}[/tex]
Mass of octane needed = 49.87 g
