Calculate CO2 Mass from Gasoline Combustion | Octane & CO2 Problem Solved!

  • Thread starter Thread starter JABEMT
  • Start date Start date
  • Tags Tags
    Co2
Click For Summary

Discussion Overview

The discussion revolves around calculating the mass of CO2 produced from the combustion of gasoline, specifically octane (C8H18). Participants explore the stoichiometric relationships involved in the combustion process and the conversion of mass to CO2 output, addressing both theoretical and practical aspects of the calculation.

Discussion Character

  • Homework-related
  • Mathematical reasoning
  • Debate/contested

Main Points Raised

  • One participant attempts to calculate the CO2 mass using the mass of gasoline and the stoichiometry of the combustion reaction, but expresses confusion over the conversion steps and the final result.
  • Another participant suggests determining the percentage of carbon in gasoline (isooctane) to find the moles of CO2 produced, indicating a potential error in the initial calculations.
  • A third participant reiterates the calculation process, providing a stoichiometric equation and deriving a different mass of CO2, which leads to further discrepancies in the answers.
  • One participant claims that the correct answer is 127 kg or 278 lb, aligning with the initial claim but highlighting the variations in responses among participants.

Areas of Agreement / Disagreement

There is no consensus on the correct mass of CO2 produced, as participants present differing calculations and results. Some agree on the final answer of 127 kg or 278 lb, while others challenge the methodology and results, indicating ongoing disagreement.

Contextual Notes

Participants express uncertainty regarding the atomic weights and molecular weights used in calculations, as well as the stoichiometric ratios. There are unresolved steps in the calculations that contribute to the differing results.

JABEMT
Messages
1
Reaction score
0
I have the answer to the problem... only my problem is I can figure out how in the world world they came up with it. Here it is... I am sure it a pretty easy equation... only I don't get it!


Calculate the mass of CO2 produced by the combustion of a tank of gasoline. Assume the mass of gasoline is 41.0 kg and that gasoline is pure octane (C8H18); 1 lb =454 g. Express your answer rounded to the nearest whole number. Do not include units with your answer.

Correct answer: 278

I have tried converting the 41.0kg into grams and got .041g.
I found the atomic mass of CO2 as 44 and X by 8 (research found Every molecule of octane makes eight molecules of CO2) which = 352.

Also the Octane has a weight of 144.

So I took .041g X (352/144)= 0.1


WHat am I missing?
 
Physics news on Phys.org
Find out what percentage of gasoline (isooctane) is carbon. Use atomic weight for carbon and hydrogen and formula wt for isooctane.
This is the carbon source for all of the CO2 produced.

The percent of gasoline that is carbon expressed in moles will equal to the moles of CO2.

Also, recheck your formula wt. for isooctane... I get 114.
And... I think the answer is wrong. I get 138 kg or 304 lb.
 
Last edited:
JABEMT said:
I have the answer to the problem... only my problem is I can figure out how in the world world they came up with it. Here it is... I am sure it a pretty easy equation... only I don't get it!


Calculate the mass of CO2 produced by the combustion of a tank of gasoline. Assume the mass of gasoline is 41.0 kg and that gasoline is pure octane (C8H18); 1 lb =454 g. Express your answer rounded to the nearest whole number. Do not include units with your answer.

Correct answer: 278

I have tried converting the 41.0kg into grams and got .041g.
I found the atomic mass of CO2 as 44 and X by 8 (research found Every molecule of octane makes eight molecules of CO2) which = 352.

Also the Octane has a weight of 144.

So I took .041g X (352/144)= 0.1


WHat am I missing?

2 C8H18 + 25 O2 = 18 H2O + 16 CO2

molecular mass of Octane is (8x12 + 18) grams/mole

41000.0 grams Octane (1 mole/(114 grams)(16 moles CO2/2 moles Octane)(44 grams CO2/1 mole CO2)=127 kg

Now we're all getting different answers. I used the stoichiometric equation however.
 
GCT has it right. The correct answer is 127 Kg or 278 lb.
 

Similar threads

Automotive Loss of gaseous volume because of fuel combustion
  • · Replies 2 ·
Replies
2
Views
2K
Calculate the mass of CO2 produced from the complete combustion
  • · Replies 1 ·
Replies
1
Views
3K
How Do I Calculate the Volume of Air Needed for Complete Combustion of Gasoline?
  • · Replies 1 ·
Replies
1
Views
2K
Sig Figs in Chemistry: Calculate Mass of O2 from Gasoline
  • · Replies 4 ·
Replies
4
Views
2K
What Is the Energy Difference Between Octane and Methanol as Fuel Alternatives?
  • · Replies 3 ·
Replies
3
Views
4K
How Does Fossil Fuel Combustion Impact Atmospheric CO2 Concentration Annually?
  • · Replies 6 ·
Replies
6
Views
7K
How Much CO2 is Produced in a Combustion Reaction with 93% Yield?
  • · Replies 1 ·
Replies
1
Views
4K
Calculate mass of NaHCO3 when losing CO2 in experiement
  • · Replies 4 ·
Replies
4
Views
8K
Mean molar mass after combustion in a combustion engine
  • · Replies 1 ·
Replies
1
Views
3K
Thermodynamics.... Constant volume pressure of combustion
  • · Replies 33 ·
2
Replies
33
Views
9K