Question

A newspaper article about the danger of global warming from the accumulation of greenhouse gases such as carbon dioxide states that "reducing driving your car by 20 miles a week would prevent release of over 1000 pounds of CO 2 per year into the atmosphere." Is this a reasonable statement? Assume that gasoline is octane (molecular formula is C 8 H 18 ) and that it is burned completely to CO 2 and H 2 O in the engine of your car. Facts (or reasonable guesses) about your car's gas mileage, the density of octane, and other factors will also be needed.

Answer 1

Mass of CO2 produced = 944.43 -lb/year

Since 944.43 -lb is close to 1000 -lb, it is a reasonable statement.

Step-by-step explanation:

Assumptions:

Car mileage = 20 miles/gallon:

Density of gasoline = 0.702 g/ml

Volume of gallons per week = (20 miles/week) / (20 miles/gallon) = 1 gallon/week

Volume of gasoline per year = 52 weeks * 1 gallon/week = 52 gallons

1 gallon = 3.8 litres or 3800 ml

52 gallons = 52 * 3800 = 197600 ml

Mass of gasoline = volume *density

Mass of gasoline = 197600 ml * 0.702 g/ml

Mass of gasoline = 138715.2 g

Equation of reaction:

2C8H18 + 25O2 ---> 16CO2 + 18H2O

2 moles of octane produces 16 moles of CO2

Molar mass of octane = 114 g/mol; molar mass of CO2 = 44 g/mol

114 * 2 g of octane = 44 * 16 g of CO2

138715. 2 g of octane produces = (138715.2 * 44 * 16) / 114 * 2 of CO2

Mass of CO2 produced = 428313.6 g of CO2 = 428.3136 Kg

Mass of CO2 produced in -lb weight = 428.3136 * 2.205

Mass of CO2 produced per year = 944.43 -lb CO2

Since 944.43-lb is close to 1000 -lb, therefore, it is a reasonable statement.