In: Chemistry
A website promoting the use of alternative energy vehicles and hybrid technologies claims that, \"A typical automobile in the USA uses about 500 gallons of gasoline every year, producing about 5 tons of carbon dioxide.\" To determine the truth of this statement, calculate how many tons of carbon dioxide are produced when 500.0 gallons of gasoline are combusted. Assume that the primary ingredient in gasoline is octane, C8H18(l), which has a density of 0.703 g·mL^ –1
HINT:
Generate a balanced chemical equation for the combustion of octane. The reactants will be C8H18+ O2, and the products will be CO2+ H2O. Using the mole ratios from the balanced equation, perform the correct unit conversions to arrive in tons of carbon dioxide. Note that : 1 gallon = 3785.4 cm3 1 lb = 453.6 g
1 USA gallon = 3.7854liters
500gallon = 500*3.7854 = 1892.7liters
mass of octane = volume * density
= 1892.7*703 = 1330568g of octane
molar mass of octane = 114g/mole
no of moles of octane = W/G.M.Wt = 1330568/114 = 11671.65
moles
2C8H18+ 25O2--------> 16Co2 + 18H2O
2 moles of C8H18 on combustion to produced 16 moles of Co2
11671.65 moles of C8H18 to gives = 16*11671.65/2 =93373.2moles
of Co2
mass of Co2 = no of moles * gram molar mass
= 93373.2*44 = 4108420.8g = 4108Kg = 4108*0.00110231 =
4.53tons