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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Why can wood burn all the way to charcoal instead of just creating a passivating charcoal layer?

I know burning to charcoal is actually incomplete combustion because charcoal can also burn. When a strike anywhere match burns, it burns all the way to charcoal but the charcoal doesn't further burn. ...
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7answers
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Why doesn't water burn?

Hydrogen is flammable, and for any fire to burn it needs oxygen. Why does a compound made of hydrogen and oxygen put out fires instead of catalyzing them? I understand that hydrogen and water are ...
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Oxidation of malonic acid

Question How many grams $\ce{CO2}$ will result when burning $\pu{100 g}$ malonic acid? The formula for malonic acid is $\ce{C3H4O4}$ so 3 $\ce{CO2}$ molecules should result from oxidating one ...
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Which one is the healthiest to operate a lantern with: kerosene, diesel or sunflower oil?

Given a lantern (originally made for kerosene) however, I'm looking for the fuel which is the safest for indoor use. I've already tried different kinds, and found three of them that burn just as ...
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1answer
76 views

Are the odours added to natural gas completely flammable?

I live in Australia, where both electricity and natural gas are common forms of household energy. An odour is added to the natural gas as a safety precaution since it is otherwise almost undetectable. ...
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1answer
154 views

What would an ammonium sulfide fire look like?

I am writing a novel and the climax involves killing my protagonist in an explosion. My science knowledge is poor but I believe my scenario is entirely plausible except possibly a couple of details. ...
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1answer
4k views

Why isn't CO2 flammable? [closed]

Given that $\ce{CO2}$ is comprised of carbon and oxygen, why isn't it a flammable gas?
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143 views

Why would Ammonium Nitrate spontaneously combust/detonate when damp?

Why would small amounts (1g or less) of Ammonium Nitrate spontaneously combust/detonate when damp? Possible temperature excursions to +70degC. Unfortunately I cannot give you the context for ...
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0answers
108 views

Making solid fuel out of sugar

I recently tried to make a cheap solid fuel out of sugar. First I attempted burning the sugar cube directly, which did not work well even using a blowtorch. This was expected. Then I attempted to use ...
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1answer
7k views

Combustion of saturated hydrocarbons vs combustion of unsaturated hydrocarbons

I read in my science book that saturated hydrocarbons burn with a blue flame (indicates complete combustion) and unsaturated hydrocarbons burn with a yellow flame (indicates incomplete combustion) due ...
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1answer
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What happens when you 'burn' ash?

This popped into my my mind while watching a match burn (don't ask me what I was doing with a burning match...). Now as I know it, 'ash' is what you call the residual, grey-black powdery material ...
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1answer
70 views

Smoldering Combustion

Does smoldering combustion only occur in an environment where oxygen levels are low? Will it always transition into flaming combustion (whenever there is ample supply of oxygen? Or can it keep ...
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1answer
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How can solids undergo combustion if it only occurs in the gas phase?

According to the smoldering Wikipedia article, flaming combustion occurs in the gaseous phase. I know butane undergoes flaming combustion in a Bunsen burner because it's a gas, but how can wood ...
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2answers
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What is the empirical formula of the polyethylene?

Polyethylene is a polymer of only carbon and hydrogen. If 2.300 g of the polymer is burned in the oxygen it produces 2.955 g H2O and 7.217 g CO2. What is the empirical formula of the polyethylene? ...
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1answer
107 views

Why don't the products of combustion stop combustion?

We know that combustion of fuels give water and carbon dioxide (during combustion of hydrocarbon) as a byproduct, but why don't these byproducts stop combustion?
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Can flames be colored black?

Most of us here would know that flames can be colored by adding an appropriate salt to the 'fuel' or by simply introducing it into a flame. Boron and Barium salts give the flame a green tinge, ...
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1answer
278 views

Release of sulfur dioxide from odored fuel gases

Often, fuel gases such as butane and natural gas (methane) are mixed with some foul-smelling impurities such as thiols (mercaptans) and hydrogen sulfide. Presumably, anything containing sulfur would ...
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2answers
2k views

How to calculate the amount of substances product produces from the masses and amounts of starting materials?

Calculate the amount of carbon dioxide formed when we burn 1 mole of carbon in the presence of 16 g of dioxygen. $$\ce{C + O2 -> CO2}$$ 1 mole of carbon means 12 g. Therefore amount of ...
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1answer
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Incense Stick vs Candle

*Not sure whether to put this on Phy or chem.. * What exactly happens when you light an incense stick? How is this different from a candle, or embers for that matter? From what I understand, a ...
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1answer
1k views

Propan-1-ol Heats Objects Faster than Propan-2-ol. Is this an anomaly?

After conducting a practical revolving around burning alcohols, I found that propan-1-ol heated the 50 mL of water to 60 °C about 1 min faster than propan-2-ol. The experiment was controlled as much ...
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0answers
974 views

Sugar burning with the assistance of ash

If a plain pile of sugar (or a sugar cube) is heated with a torch, it just melts and gives off smoke. However, if some paper or wood ashes are added, it burns quite easily. What are the ingredients of ...
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1answer
309 views

Incomplete combustion

I cannot find a definitive equation that describes the incomplete combustion of a hydrocarbon. Equations $1$, $2$ and $3$ are some of the variations I have found. Is it, $(1)$ $\ce{C_xH_y + O_2 \...
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1answer
134 views

Is a gas leak considered incomplete combustion?

This may be a dumb question, but if I leave the stove-top valve open (or I have a gas leak due broken tubing), would that be considered incomplete combustion? From my knowledge, I figured a reaction ...
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0answers
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Relating to combustion

Can i make a gel/liquid/any kind of solution which supports combustion but at the same time protect the surface from getting burnt? I wanted to light a log on fire using some kind of fuel which allows ...
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Why don't we produce water from combustion?

My friend who is a biology major proposed that we can produce water by burning any hydrocarbure or wood or ... to obtain water. $\color{red}{f(x,y,z,\Lambda)}\ce{C}_x\ce{H}_y\Lambda_z+\color{red}{g(...
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4answers
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Does any known substance ignite on cooling?

As the title says, I'm interested in knowing if there is any substance — or combination of substances — that ignites (or even increases its chance of spontaneous ignition) when cooled. I've never ...
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1answer
105 views

Given a theoretical combustion engine, how can I calculate the output of this engine depending on the fuel it uses?

I'm writing a Minecraft mod (for those who don't know, it's sort of like a smaller "program" that loads into the Minecraft game and expands it, by adding other things to it). My question is: consider ...
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3answers
848 views

How is combustion speed regulated in solid propellants?

My question on Space.SE didn't yield anything I didn't know already: the secondary regulation mechanism – grain (cross-section shape) of the propellant, changing the area of open surface of the ...
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2answers
371 views

Propane Combustion in a Gas Grill with Irregular Flameouts

I'm troubleshooting a problem with a brand-new propane gas grill that is experiencing flameouts and making puffing/popping sounds. I'm asking here because I want to understand the basic chemistry ...
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4answers
4k views

Can ethanol alone be used as Fuel?

Ethanol is a clean fuel and added as an additive to petrol. Why can't ethanol itself be used as fuel?
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2answers
696 views

Plastics and Cotton

Plastics melt on heating and Cotton burns. When do substances burn with flame? Should they always contain volatile compounds for them to create the Flame?
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0answers
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ZnO spontaneous combustion during transport

I found your contact information researching $\ce{ZnO}$ reactions. I was hoping you could please help me or orient me in the right direction to find an answer to my problem. The company I work for ...
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2answers
4k views

Why do the alkali metals form different products upon combustion in air?

From Wikipedia's article on sodium: When burned in dry air, it forms primarily sodium peroxide with some sodium oxide. We know that sodium has a strong reducing capacity, so why does it produce a ...
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1answer
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How to fake a fireball? [closed]

It is for my book: i need some material, what would burn very bright for a long time, what could it be? Or another advises, how could a character fake a fireball, seen in the sky for a long time?
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1answer
81 views

How much “cleaner” does summer fuel burn?

Well, it's that time of year again: the switchover to "summer" fuel and resulting price increases. This EPA regulation system requires gasoline producers to blend additives into the gasoline that ...
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1answer
347 views

Gases produced by pyrolysis of cellulose

I heated cotton in a sealed container (with a small hole) over a natural gas flame. Some gases and smoke were produced. What would they probably be? I can come up with some guesses based on the ...
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1answer
203 views

Density of LPG in g/L [closed]

What is the density of LPG (in vapour state) in g/L? Please note that I'm asking about the density of vapour LPG when it comes out of the cylinder. NOT the liquefied density!
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1answer
226 views

Why there is an Upper Explosive concentration Limit?

If we have a mixture of combustible gas (let's say it's methane) and air, what is the physical explanation for having a upper concentration limit? I found this document: Lower and upper explosive ...
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1answer
114 views

How can I obtain oxygen gas from plagioclase

I would like to know if there is a possibility to decompose plagioclase to obtain oxygen gas to be used in a combustion reaction? I know that oxygen represents $47\%$ of the weight of 1 mole of ...
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2answers
94 views

Combustion that generates no gas?

I'm learning on my own with Chemistry The Central Science, 13th ed. book. So far it's going well. I've come across something I don't think I understand. I've googled and "stackechanged" with no avail....
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0answers
59 views

Combustibility of gas/carbon dioxide mix

Via electrolysis I produced an ethane/hydrogen/carbon dioxide mix. Normally, there is 1 part ethane, 1 part hydrogen and 2 parts carbon dioxide. If I simply used a Bunsen burner with air hole closed ...
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1answer
433 views

Exhaust gas purification

I'm more asking this because I'm not sure how far science has come. Pretty much, I've been thinking about the car exhaust system lately. The two main components that lead to hazards from cars are $\ce{...
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1answer
567 views

Output of the Sugar & Sulfuric Acid Reaction?

When a reaction of sugar and sulfuric acid occurs, some form of carbon is produced. Is this carbon bonded as graphite? If not, than what is it bonded as? $\ce{C6H12O6 ->[H2SO4] 6C + 6 H2O }$
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2answers
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What causes transition from smoldering combustion to flame combustion?

What causes the transition from smoldering combustion to flame combustion? From what I have read about it is that, smoldering combustion gives off a lot of flammable gases, primarily, Carbon Monoxide,...
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Meaning of Flammability Limits and reaction in Air of Ammonia

I have read on Wikipedia that the flammable limits of gaseous ammonia are between 15–25% and I have also read that the autoignition temperature is $651\rm~^\circ C$. And that the combustion of ...
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2answers
59k views

Why do unsaturated hydrocarbons burn with a sooty flame while saturated hydrocarbons burn with a clear flame when burnt in the air?

Why do saturated hydrocarbons burn with a clean flame while unsaturated hydrocarbons burn with a sooty flame when burnt in air? My chemistry book says that it happens due to the amount of carbon ...
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2answers
259 views

Why are fires smokey?

Combustion, in chemical terms, is a reaction with a certain molecule and oxygen, and it produces, energy, $\ce{CO2}$, and $\ce{H2O}$ (That's how I learned it at least). So what makes a fire'smokey'? I ...
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1answer
289 views

Can carbon subnitride be used as a fuel with similar properties to gasoline?

I am trying to figure out if Dicyanoacetylene, aka carbon subnitride, aka $\ce{C4N2}$, can have a similar reaction with air as gasoline, or if it only creates a lot of heat but not much expansion? As ...
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1answer
8k views

Why does shaking a match put the fire out?

Move a match slowly and nothing happens but if you shake it violently the fire will extinguish. Oxygen makes fire grow so why does waving a flame through the oxygen rich air put the fire out? Does ...
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2answers
32k views

What temperature is required to burn pencil lead graphite?

I tried to burn a bunch of 8B pencil lead in a gas flame the other day. None of it actually caught fire, but being made of carbon (in the form of graphite) should cause it to burn, as graphite is ...

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