Chapter 9, Problem 18CI

Automobile exhaust is a major cause of air pollution. One pollutant is the gas nitrogen oxide, which forms from nitrogen and oxygen gases in the air at the high temperatures in an automobile engine. Once emitted into the air, nitrogen oxide reacts with oxygen to produce nitrogen dioxide, a reddish brown gas with a sharp, pungent odor that makes up smog. One component of gasoline is heptane, C₇H₁₆, a liquid with a density of 0.684 g/mL. In one year, a typical automobile uses 550 gal of gasoline and produces 41 lb of nitrogen oxide. (7.4, 7.8, 8.6)

a. Write balanced chemical equations for the production of nitrogen oxide and nitrogen dioxide.
b. If all the nitrogen oxide emitted by one automobile is converted to nitrogen dioxide in the atmosphere, how many kilograms of nitrogen dioxide are produced in one year by a single automobile?
c. Write a balanced chemical equation for the combustion of heptane.
d. How many moles of gaseous CO₂ are produced from the gasoline used by the typical automobile in one year, assuming the gasoline is all heptane?
e. How many liters of carbon dioxide at STP are produced in one year from the gasoline used by the typical automobile?

Two gases found in automobile exhaust are carbon dioxide and nitrogen oxide.