To compare the emissions of a propane-burning car to that of a gasoline-burning car, we need to calculate the amount of CO2 produced from a single tank of gas for each fuel. Here's how it can be done:
Propane:
A single tank of propane contains 40.0 kg of fuel. From the balanced equation for propane combustion, we know that for every 1 mole of propane burned, 3 moles of CO2 are produced.
We can use the molar mass of propane (44.1 g/mol) to convert the amount of fuel to moles:
40.0 kg × 1000 g/kg ÷ 44.1 g/mol = 909.1 moles
So, 909.1 moles of propane would be burned, producing:
909.1 moles × 3 moles CO2/1 mole propane = 2727.3 moles CO2
Finally, we can use the molar mass of CO2 (44.0 g/mol) to convert the amount of CO2 to grams:
2727.3 moles × 44.0 g/mol = 120167.2 g
And then, to convert the amount of CO2 to kilograms:
120167.2 g ÷ 1000 g/kg = 120.2 kg CO2
So, from a single tank of propane, 120.2 kg of CO2 would be produced.
Gasoline (2,2,4-trimethylpentane):
A single tank of gasoline contains 40.0 kg of fuel. From the balanced equation for gasoline combustion, we know that for every 1 mole of gasoline burned, 8 moles of CO2 are produced.
We can use the molar mass of gasoline (114.2 g/mol) to convert the amount of fuel to moles:
40.0 kg × 1000 g/kg ÷ 114.2 g/mol = 349.6 moles
So, 349.6 moles of gasoline would be burned, producing:
349.6 moles × 8 moles CO2/1 mole gasoline = 2796.8 moles CO2
Finally, we can use the molar mass of CO2 (44.0 g/mol) to convert the amount of CO2 to grams:
2796.8 moles × 44.0 g/mol = 122957.1 g
And then, to convert the amount of CO2 to kilograms:
122957.1 g ÷ 1000 g/kg = 122.9 kg CO2
So, from a single tank of gasoline, 122.9 kg of CO2 would be produced.
From the calculations above, we can see that a car burning gasoline produces slightly more CO2 than a car burning propane from a single tank of fuel.