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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7
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4answers
491 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 ...
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1answer
272 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 ...
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1answer
700 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 ...
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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. ...
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1answer
156 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
122 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
789 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
301 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
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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
474 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
46k 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
6k 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 ...
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3answers
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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
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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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2answers
17k 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
3k 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 ...
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1answer
9k 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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3answers
9k views

How can metals like magnesium and sodium burn underwater? [closed]

Please answer with as much detail as possible. I can't find the answer anywhere else and I need it for an essay. Any websites I have found have conflicting answers. One said that they don't actually ...
3
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1answer
808 views

I heard aluminium doesn't produce fumes when burnt but the opposite happened, how?

One day I took aluminium foil(sanitary brand, don't know if you've heard it) then I casually burned it over a gas lighter then it burned and gave off Grey fumes and the foil became a dull Grey ...
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1answer
211 views

Questions about combustion and isotopic abundance

the combustion of 0.214g of sulfur provided exactly 0.428g of sulfur dioxide. After a second try, 0.782g of SO2 was obtained. What mass of sulfur was used? The combustion of lithium forms lithium ...
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1answer
237 views

Can water be ignited in an ozone atmosphere?

According to my calculations, the reaction $\ce{H2O + O3 -> H2O2 + O2}$ should be favourable under standard conditions. However, I am told that the reaction is probably very slow in solution since ...
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1answer
830 views

Heat of combustion per mole and per kilogram

I need to calculate the heat of combustion per mole and per kilogram of complete combustion of, say, X. I write reaction : $\ce{X + O2 -> ... + Q}$ Find Q using Hess law Now, what do I do after ...
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2answers
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Reaction involved in Combustion of Nitrocellulose-Nitroglycerine(NCNG) solid propellant?

I'm working on solid propellant based microthrusters and I am using NCNG as the solid propellant. I want to know the reaction taking place and the mass fraction of the products obtained on combustion ...
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1answer
116 views

Is the end of a cigarette on fire when lit?

Is the end of a cigarette on fire when it is lit? Or is it smoldering? Is there a chemical difference between the two?
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3answers
5k views

How much Carbon Dioxide would be required to displace enough oxygen to prevent ignition?

In air, how much $\ce{CO2}$ would be required to prevent a match to light or a butane lighter to work? I have a basement office that is unusable because of an apparent lack of oxygen, currently it ...
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1answer
1k views

How much activation energy is required to combust propane?

According to WolframAlpha, the change in enthalphy in the combustion of propane is -2220 kJ/mol. How do I calculate the activation energy required start the reaction in the first place? Do you use the ...
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3answers
22k views

C + O2 is equal to C + O, how is that possible

C + O = CO2 . This is because carbon has valency of 4 while oxygen has valency of 2. When they react the valencies are criss crossed which means we will get C2O4 but this is simplified to CO2. But ...
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3answers
47k views

CH4 + O2 => CO2 + 2H2, what's wrong with it?

It says in my textbook that: $$\ce{CH4 + 2 O2 -> CO2 + 2 H2O}$$ which seems like a displacement reaction to me. Shouldn't the reaction be: $$\ce{CH4 + O2 -> CO2 + 2 H2}$$ since $\ce{4H}$ ...
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1answer
14k views

Incomplete Combustion products

In class we performed an experiment which I am unable to understand the results for Why does the the amount of soot produced vary? What is the amount of soot produced dependent on? Experiment: ...
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4answers
2k views

Role of heat in combustion

What role does heat play in the combustion process.Specifically, does the amount of heat determine whether complete or incomplete combustion occurs, and is the amount of heat impacted by the amount ...
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1answer
300 views

Combustion of thiazole

I am learning Chemistry from a book Heterocyclic compounds and I have bumped onto a following image with given tasks: What is the balanced reaction? What is the RMM of thiazole? What is the fuel-air ...
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1answer
123 views

Could this be a feasible fuel system?

First off, please forgive me, I am a chemistry novice! Overall Process Fuel for the system is distilled water Split water into Hydrogen and Oxygen (electrolysis or similar process) Exhaust Oxygen ...
5
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1answer
643 views

Maximum pressure that can be produced by a combustion reaction

Multiple-chamber artillery can launch a projectile with energies much higher than single-chamber guns. I'm interested in setting a fundamental upper bound on the energy that a chamber (of a known ...
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3answers
433 views

Can oxygen burn in hydrogen?

Most combustion happens involves the fuels burning in an oxidant. But there seems to be no reason that it cannot happen in the opposite way. Are there any experiments on oxygen burning in hydrogen? Or ...
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1answer
4k views

Limiting Reactants without a given mass

This is a question I have for Chemistry homework, but I don't understand how to solve it without a given mass. I narrowed the choices down (see below _) I know a limiting reactant well limits the ...
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1answer
485 views

What would cause a sudden drop in humidity in my home?

I have a ventless propane heater newly installed in my home, which has been an increasingly source of paranoia for me (constant condensation on the windows, worries about carbon monoxide poisoning). ...
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1answer
206 views

What are the known atomic oxygen species?

I'm interested in chemical reaction mechanism with more exotic particles. The Wikipedia page seems to imply that the normal atomic oxygen is $O(^3P)$, is that right? I also came across $O(^1D),O(^1S)...
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1answer
3k views

Why does a wood fire create benzene?

According to this article called The Fireplace Delusion a wood-fire will create benzene. This surprised me and I can't find an article online that explains the chemical reaction behind that.
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2answers
19k views

Is it possible to light a match by scratching it on hard surfaces, like they do in movies?

In movies cool guys don't need a matchbox − they just light a match by scratching it on whatever hard surface − concrete walls, wooden bar tables, leather belts, etc. Is it just a movie trick, or is ...
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2answers
8k views

What product will be produced when a sucrose and potassium nitrate mix burns? [closed]

What product will be obtained get when a sucrose and potassium nitrate mix, which are the ingredients for smoke bomb, are burned in a combustion container? $$\ce{KNO3 + C12H22O11 -> ?}$$
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1answer
174 views

Temperature & time necessary to carbonize all organics

Suppose that I have a cast-iron pot which my awful roommate has vigorously scrubbed with soap and left to soak in soapy water over the weekend. The seasoning has been destroyed and replaced with awful-...
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1answer
517 views

Variation of cone angle with concentration of fuel-air mixture

A stoichiometric fuel-air mixture flowing in a Bunsen burner forms a well-defined conical flame. The mixture is then made leaner. For the same flow velocity in the tube, how does the cone angle change?...
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2answers
35k views

Why is O2 the supporter of combustion?

It's there in every high-school textbook: $\ce{O2}$ is the supporter of combustion. Without $\ce{O2}$ combustion cannot take place. Why? And why only $\ce{O2}$? Why not some other element? And, what ...
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3answers
398 views

Open flame combustion in bizarro world

Humans typically achieve combustion by starting a chemical reaction of a fuel (often a carbon $\ce{C}$ containing fluid like methane $\ce{CH4}$), which is is brought into an an oxidizer (a gas ...
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3answers
4k views

Can natural gas appliances run on Hydrogen?

Can natural gas appliances run on Hydrogen? If so, does the appliance have to be modified and how significant of a modification would it need? Thanks
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3answers
13k views

Are there substances that cannot undergo combustion?

Are there substances that cannot undergo combustion? If so, what are they?
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1answer
1k views

How can diesel fuel produce less carbon monoxide but more carbon particulates?

My guess at why diesel produces less carbon monoxide is that more heat is required for combustion of diesel fuel, so there is less incomplete combustion. Therefore rather than carbon monoxide being ...
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1answer
119 views

What determines a substance's energy of activation with air?

Ice will melt when heat is applied; paper will catch fire. In trying to figure out why — what the difference is between things that melt and things that catch — I found "Burn, Char, Melt" by Roberto ...

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