Popular Science magazine said that 19 lbs of carbon dioxide are released into the atmosphere for each gallon of gasoline burned. Anyone with a basic knowledge of science knows that this is ridiculous (unless they've found a flaw in the law of conservation of mass).
2006-08-17 15:46:59 · 8 answers · asked by ghetifal 1 in Cars & Transportation ➔ Other - Cars & Transportation
Some of the mass of the CO2 probably comes from free diatomic oxygen in the atmosphere. The gasoline contributes the carbon, but the oxygen comes from the air.
Carbon has a molecular weight of 12. One oxygen atom is 16. Then CO2 is 12+(2)16 = 12+32 = 44.
44/12 = 3.667
That means for every pound of carbon burned, there will be 3.667 pounds of CO2 gas released.
About 16% of the weight of a gallon of gas is hydrogen. If the gallon of gas weighs 6.6 pounds, then the hydrogen in it weighs 1.1 pounds, and the carbon will weigh about 5.5 pounds.
If all 5.5 pounds of carbon turns into CO2 during the combustion, the weight of the CO2 will be 20 pounds. (The weight of the oxygen used up will be about 14.5 pounds.)
Of course, the combustion process isn't perfectly efficient. Some of the gas won't burn, and some of what does burn will become carbon monoxide instead of carbon dioxide. But 19 pounds isn't an unreasonable figure for the magazine article to mention.
And that 1.1 pounds of hydrogen can combine with 8.8 pounds of oxygen from the air to produce 9.9 pounds of water vapor.
The formation of both CO2 and water vapor from the complete combusion of one gallon of gasoline removes 24.5 pounds of free oxygen from the atmosphere.
2006-08-17 16:41:48 · answer #1 · answered by David S 5 · 0⤊ 0⤋
P.M. is correct. When the hydrocarbons burn, there is a chemical change taking place.
There is a change from the carbon chain being stripped from the hydrogen and re-assembling with the O2. O has mass as well.
Also expelled from the tail pipe is H2O. Water; about 8 to as much as 11 gallons of it for every gallon of fuel. There is no water in the fuel so it must come from the air mass (moisture in the air) and the chemical process that occurs in the combustion process Hydrogen + Oxygen = H2O)
The natural result of COMPLETE combustion (something an internal combustion is not yet capable of) is CO2 and Water (H2O) Vapor.
2006-08-18 00:41:44 · answer #2 · answered by Ironhand 6 · 0⤊ 0⤋
There is no flaw -
Gasoline weighs about 700g/litre with a generalised formula of CnH2n. This allows for some aromatics and olefinics as well as the base paraffins.
A "gallon" depends on whether you are talking US Gallon (3.75lt) or Imperial Gallon (4.54lt), which equates to either 2.65kg or 3.18kg of gasoline.
Based on the relative masses of carbon and hydrogen, this means that there is (about) 2.27kg or 2.73kg of carbon per gallon (once again, depending on the type of gallon you are talking about).
OK, so CO2 = 1 carbon atom + 2 oxygen atoms
or
CnH2n + (1.5)nO2 -> nCO2 + nH2O
O2 has a molecular weight (ie molar mass) of 32. So for every 12grams of carbon you use 32grams of oxygen, therefor:
2.27kg of carbon reacts with 6.06kg of oxygen to give 8.33kg of CO2.
8.33kg x 2.2lb/kg = 18.32 lb of CO2
2.73kg of carbon reacts with 7.28kg of oxygen to give 10kg of CO2 or 22lb of CO2.
Mass conserved. Not so ridiculous. It would appear that you lack a basic knowledge of science.
If only americans would adopt SI units the world would be so much simpler!
2006-08-18 02:01:01 · answer #3 · answered by Bruce H 3 · 0⤊ 0⤋
6 pounds / gallon, maybe part of the combustion process includes the o2 in the air as well,since it is co2.So that leaves about 17 pounds of o2. not sure how much volume of air that is.according to web site below 7392 liters of 02 is burned for every gallon of gas combusted at 100% efficiency. weight of air is approximately 0.00129 gram/cubic-centimeter (g/cm3), OK i know that's mostly nitrogen, but that does not com bust. so 7392 liters of oxygen=7.3 kilograms or 14.6 pounds. so 14.6 of + 6 pounds gas = 20.6 pounds , OK I'm off , well maybe I'm not at sea level.
Jeesh who said stoned people were dumb. Legalize it dude
2006-08-17 23:14:44 · answer #4 · answered by Patrick Bateman 3 · 0⤊ 0⤋
I use to know the answer, but have since forgot. If my lack of memory serves me correctly, a gallon of gasoline weighs about 6.9lbs.
2006-08-17 22:53:27 · answer #5 · answered by MARIA 4 · 0⤊ 0⤋
One gallon of gas weighs about 6.25 pounds. The weight fluctuates with temperature and octane, but this figure is good enough for government work.
2006-08-17 22:52:23 · answer #6 · answered by Scott K 2 · 0⤊ 0⤋
Like all goody good liberals , when it's for the good of the planet and it's people tnen fudgeing on facts is allowed and will not be challenged by any liberal run regulartory body or group. They know better what's good for us! Just look at the dour predictions by the lot that never got close to reality!
2006-08-17 23:05:45 · answer #7 · answered by Anonymous · 0⤊ 2⤋
Gas weighs about 7lbs per gallon. I don't think their calculations are right.
2006-08-17 22:51:46 · answer #8 · answered by Shawtime 2 · 0⤊ 0⤋