Questions tagged [combustion]

For questions about the combustion of an organic molecule or inorganic substance. Do not use this tag if your question is about the [stoichiometry] of a combustion reaction, or for the calculations of [thermodynamics] functions (like enthalpy change).

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2answers
110k views

What are the differences between diesel and unleaded gasoline?

I am curious about the flammability of diesel fuel and its properties, as I don't deal with it on a regular basis (at all). In particular, I want to know how the fuel works when powering a diesel ...
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1answer
2k views

What is a kg.cal per gram, as a heat of combustion?

I see heats of combustion given in kg [dot] calories per gram molecular weight (Handbook of Chemistry and Physics, 1969-1970). I don't know how that makes sense, as I don't know what a kg cal might be....
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1answer
357 views

test tube cracked when added glycerin to potassium permanganate

I am not expert in chemistry.I learned about combustion in reaction when added glycerine to potassium permagnet.I tried it at home, I took potassium permagnet in test tube and when I added glycerine ...
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0answers
137 views

Methylation of perchlorate

I am exploring (non-experimentally!) the methylation of a perchlorate precursor, either the acid or pre-existing salts, to produce the alkali methyl perchlorate. The methylating agent would be methane ...
5
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1answer
243 views

Can a flame start on water (video included)?

Can a flame a start on a wet piece of paper immersed in water? The video is shown below (not the full video): https://youtu.be/Ey3z8z4Hxtc?t=1h27m29s This is not in English so you might not ...
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1answer
1k views

Predicting incomplete combustion?

I understand the concept of incomplete combustion and that it occurs when oxygen is not a large enough supply to allow for complete combustion. My question is: how can we model combustion properly in ...
5
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0answers
156 views

Combustion of halo-organic compound

My question is based on the Preparatory Problem Set for the 47th IChO Problem 26 - Holy War against Four Horsemen of the Apocalypse (it is on page 36). It is written that cooling of Y combustion ...
9
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3answers
20k views

Can you melt wood?

We talked about it in our chemistry class but we couldn't get to a conclusion, any help?
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1answer
5k views

Burning a diamond produces how much energy?

How much energy is produced by burning a 1 ct. diamond? I'm trying to figure out how much energy to build the diamonds in a biological process. See here: https://worldbuilding.stackexchange.com/...
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2answers
12k views

Air contains 20 % O2 by volume. How many cm³ of air will be required for oxidation of 100 cm³ of acetylene?

Air contains 20 % $\ce{O2}$ by volume. How many cm³ of air will be required for oxidation of 100 cm³ of acetylene? (a) 1064 cm³ (b) 212.8 cm³ (c) 500 cm³ (d) 1250 cm³ Answer: (d) My solution: ...
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1answer
1k views

Is it possible to find fire outside the Earth?

Excuse me if the question is silly, I have very little knowledge of chemistry. We can find oxygen in many places in the universe, but all the combustibles we use to light fire seems to be organic: ...
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2answers
1k views

Can covalently bonded hydrocarbons be influenced by a magnetic field?

I am doing a University project on Magnetically Assisted Combustion and am curious to know more about how magnetic fields may or may not affect gases such as butane and propane. I think I am right ...
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2answers
991 views

Chemical equilibrium for simultaneous dissociation reactions

While calculating the adiabatic flame temperature for the following combustion reaction: $$\ce{\Phi\, C2H6 + $3.5$\,(O2 + $3.76$\,N2) -> $a$\,CO2 + $b$\,CO + $d$\,H2O + $e$\,H2 + $f$\,O2 + $g$\,N2}...
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1answer
58 views

“Alkanes must be vaporised before they will burn” - what does this mean?

What does this sentence mean - I assumed that burning vaporised something? If something is vaporised, isn't that turning it into a gas? How can you burn a gas? This is a sentence in my AS Chemistry ...
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4answers
2k views

Can paper burn without oxygen or air?

If you put a paper inside an oven vacuum packed and go beyond $250~\mathrm{^\circ C}$, will it burn? There's no oxidizer. If not, what will happen?
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2answers
885 views

Combustion in liquid state

Normally, we think of combustion as occurring only in the gas phase. I think I understand the main reason for this - in the gas phase it's very hard for a bimolecular reaction to produce a single ...
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2answers
21k views

Equivalence ratio explained

To let you know where I'm coming from: I haven't studied chemistry since high school. I am now studying something else, but I have a dataset coming from your field and I would like some help in ...
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0answers
30 views

How do things heat one another? [duplicate]

For example, how does a gas stove heat a metal pot? A combustion reaction between the gas and the air takes place, and this releases energy due to new chemical bonds being formed. Do the atoms in ...
5
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2answers
249 views

Is it possible to combust a plasma?

In what we usually consider combustion your fuel and oxidizer are always neutral, but is it possible to have a similar "explosive" combustion process where both the fuel and oxidizer have been singly ...
3
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1answer
29k views

What is the temperature of heat generated from LPG gas?

I'm working on a project and I require around 300-400 degree Celsius of temperature. As of now I'm taking the normal LPG gas that is available in our house for cooking purposes for my project, but I'm ...
3
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1answer
2k views

Creation and Combustion of Nitrocellulose

I am intending to demonstrate the formation and combustion of nitrocellulose with my high school students, however I am concerned about the potential products of the combustion equation. I have been ...
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1answer
684 views

Calculating moles of Hydrogen gas in multiple gas container

If there was a 500 mL container filled with oxygen and hydrogen so it burns completely (2H:1O), how many moles of hydrogen gas would there be if there if pressure is 101.3 kPa and the temperature is ...
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1answer
608 views

Why do internal combustion engines only burn to carbon monoxide, not dioxide?

Why don't diesel and regular car engines burn all the way to $\ce{CO2}$?
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1answer
1k views

Can we do combustion caused by limited supply of air in a lab? How?

For example Ethyne in combustion by limited supply of air $$ \ce{ 2C2H2 + 3O2 ->[\Delta] 2CO2 + 2H2O + 2C } $$ vs. $$ \ce{ 2C2H2 + 5O2 -> 4CO2 + 2H2O + Energy } $$ What are the limits ...
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1answer
108 views

Can there be active THC be trapped in the evaporator?

In relation to the vaporization of THC, when smoked, is it possible that there is any active THC residue that becomes trapped inside the evaporator after the flame goes out? Wouldn't some of the ...
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2answers
4k views

How to determine the empirical formula for terephthalic acid from its combustion products?

Terephthalic acid is an important chemical used in the manufacture of polyesters and plasticisers. It contains only $\ce{C}$, $\ce{H}$, and $\ce{O}$. In one experiment, $0.4953~\mathrm{g}$ of the acid ...
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1answer
7k views

Why do gummy bears explode when added to hot potassium chlorate?

This link shows that a gummy bear explodes when in contact with heated potassium chlorate, $\ce{KClO3}$. But what in a gummy bear creates this reaction? Also, do other foods (fruit, icing sugar...) ...
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1answer
544 views

Why does a smaller amount of propanol burn slower than a much larger amount?

Why does $30~\mathrm{mL}$ of $\ce{C3H7OH}$ burn in 1 second (inside a water jug) compared to a sixth of the amount: $5~\mathrm{mL}$ of $\ce{C3H7OH}$ (on a plate) burn in 180 seconds? Why does the ...
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0answers
149 views

Auto ignition of tert-butyl mercaptan mixed with mineral oil

I am designing an experiment that involves immersing pieces of pipe lining in a mixture of tert-butyl mercaptan (2 %) and white mineral oil (98 %) at 230 °C (the standard temperature for the test). If ...
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1answer
35 views

How significant is air decomposition on formation of nitrogen oxides?

How significant is $\ce{NO$_x$}$ formation from $\ce{O2}$ (reactant) and $\ce{N2}$ decomposition from simply heating the two as opposed to from $\ce{CO2}$, $\ce{H2O}$, (and $\ce{N2}$) dissociation? In ...
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1answer
1k views

Write the combustion equation of an organic compound

Write the combustion equation of the organic compound $\ce{C5H10O}$ I have no idea at all how to write the equation. Should I add $\ce{O2}$ to make it $$\ce{C5H10O + O2 → ... ?}$$
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4answers
649 views

How does the presence of chlorine atoms in PVC make it flame resistant?

In a paper that I'm reading, it states that: The presence of chlorine atoms in polyvinyl chloride make it flame resistant and I'm just wondering why the presence of chlorine atoms will make it ...
2
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1answer
288 views

Why is CO a major species only in fuel-rich combustion?

In fuel-rich combustion, my understanding is that enough fuel reacts and consumes all of the oxygen present. The combustion products $\ce{CO2}$ and $\ce{H2O}$ undergo dissociation until equilibrium is ...
5
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1answer
867 views

Is There a Difference in the Definition of Complete and Stoichiometric Combustion?

My question has to do with some combustion related definitions. When the term complete combustion is used, is it assumed that the combustion is stoichiometric (reactants combine perfectly), but ...
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1answer
6k views

Combustion of paraffin

Find the heat of combustion for 1 mol of $\ce {C21H44}$ in the reaction where some wax is oxidized to elemental C (soot) and water vapor. The Heat of Formation of $\ce {C21H44}$ is -476 kJ/mol. When ...
5
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1answer
3k views

Relationship between auto-ignition temperature with pressure and fuel

Experimentally it appears that increase in pressure, fuel concentration, and chain length causes AIT to decrease until a minimum where even further increase in these parameters increases the AIT. ...
2
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1answer
159 views

Greatest Energy Output Reaction to Atmosphere Air

First of all i'm no chemist, this is not homework and if you need further clarification please ask. I'll be happy to provide! Imagine that you: have 1 kg of any given chemical X A car battery A semi-...
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1answer
131 views

Additional Questions Regarding the Auto-Ignition Temperature

I had some followup questions regarding a previous post I made here regarding the auto-ignition temperature and ASTM E659 For fuel temperature below AIT, we should still have finite reactants above ...
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1answer
804 views

Mechanics behind auto-ignition temperature

I have some questions about the auto-ignition temperature for fuels. Per ASTM E659: AIT (auto-ignition temperature) is the lowest temperature at which the substance will produce hot-flame ignition ...
3
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1answer
310 views

What are the product(s) of red phosphorous when burned?

A match box lighter strip typically consists of powdered glass and red phosphorous. When this part is burned, it's residue is like a sticky dust that, when applying friction, will release smoke or ...
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0answers
3k views

Relationship between Equivalence Ratio and Adiabatic Flame Temperature for Fuel Rich Combustion

I'm reading a combustion text and would like help interpreting the following passage (diagram attached). It is regarding the relationship between equivalence ratio and adiabatic flame temperature: ...
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1answer
506 views

Do reverse reactions occur in combustion?

I am currently reading a textbook on combustion. They assume that all reactions go to completion, such that post combustion only unburned fuel/air and actual products remain. Assuming that combustion ...
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2answers
50k views

Heats of combustion and stability of rings

Which isomer would have the largest heat of combustion? A) Propylcyclopropane B) Ethylcyclobutane C) Methylcyclopentane D) Cyclohexane E) Since they are all isomers, all would have the same heat of ...
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1answer
7k views

Heat of combustion for octane

I'm a Mechanical Engineering student and I have been working on a school project but I want to go a bit beyond that and it has led me here. I'm designing an engine cylinder, and I figured I should be ...
15
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3answers
914 views

What really happens atomically in an explosion?

Let's say a room is filled with butane, I then throw a cigarette into the room. What happens to the atoms/molecules of the butane when they are in contact with the heat from the cigarette?
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1answer
4k views

Black Smoke Produced from Regular Lighter but Not Torch Lighter Applied to Copper

I have a piece of copper mesh from which I would like to remove all coatings/oils. The copper comes from a pot scrubber like this. In order to remove any residue, I held a standard bic lighter up to ...
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3answers
19k views

Why are methanol flames less visible than other flames?

The combustion of methanol tends to generate flames that are less visible than the flames generated by the combustion of other substances? My guess is that methanol burns quickly as it has a ...
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1answer
4k views

What is the mole fraction in mixture before combustion?

What is the mole fraction of $\ce{C2H6} / \ce{C3H8}$ in mixture, if both compounds reacted with $\ce{O2}$ in stoichiometric ratio? Mass of produced $\ce{CO2}$ is $1.819$ times larger than the mass of ...
15
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1answer
10k views

Why is there sulfur in black powder / gun powder?

Black powder is composed of charcoal, sulfur and a nitrate salt. The charcoal and sulfur serve as fuel and the nitrate is the oxidizing agent. However, wouldn't it be cheaper to leave out the sulfur, ...
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1answer
1k views

Can electrolyzing ice cause an explosion?

I know electrolyzing water separates it into hydrogen and oxygen. However, I am curious, if ice is electrolyzed, could it explode? My thought process is that oxygen and hydrogen bubbles would build ...

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