It is an exothermic process by which a substance is oxidized (by an oxidizing agent such as oxygen) to release a large amount of energy in the form of heat and often light.

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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 ...
-1
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0answers
15 views

Net change in moles of gas combustion of octane

I was looking at a website which says that the net change in moles is 9 for this reaction, but I don't understand why. I would have thought the change would have been the difference between 27 and 34.
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1answer
30 views

Propane Combustion

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 ...
2
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2answers
34 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?
4
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0answers
41 views

ZnO spontaneous combustion during transport

I found your contact information researching 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 produces ...
14
votes
1answer
397 views

Why does sodium produce predominantly sodium peroxide when burned 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 ...
-1
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1answer
37 views

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?
1
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1answer
29 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 ...
0
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1answer
23 views

Density of LPG in g/L

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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0answers
16 views

Why do Aerozine and dinitrogen tetroxide burn with a colorless flame?

Here is a launch of the Titan II ICBM: (Image Source: Wikipedia) Wikipedia says: The Titan II also used storable propellants: Aerozine 50, which is a 1:1 mixture of hydrazine and unsymmetrical ...
2
votes
1answer
37 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 ...
1
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1answer
56 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
20 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 ...
3
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1answer
404 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{...
0
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0answers
39 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? Edit 0: I had the wrong reaction originally. ...
3
votes
2answers
69 views

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,...
2
votes
2answers
484 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 ...
2
votes
2answers
61 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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0answers
19 views

Find the formula of a Biodiesel with these given [closed]

Biodiesel from a palm oil has an approximate formula of Cx Hy Oz. Excess air is supplied at 30 degree Celsius, 100 kPa and 85% RH. The exhaust gas leaves at 250 degree Celsius and 750 mm Hg with a ...
3
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0answers
34 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 ...
43
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1answer
5k 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 ...
0
votes
1answer
355 views

What temperature is required to burn 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 ...
0
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0answers
19 views

Can oxidizing agents act as comburents?

Comburent, to the best of my knowledge, refer to substances that catalyze combustion reactions without reacting itself or being flammable independently, such as potassium chromate. How would oxidizing ...
3
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0answers
58 views

What's the composition of gun smoke and is it dangerous?

Background I've been conducting an informal (i.e. mental) risk assessment of visiting gun ranges. There are a couple of obvious sources of hazard: Injury by bullet Hearing loss Hot casings flying ...
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0answers
54 views

combustion of natural gas and oxygen overall molar and volume ratio

I am trying to calculate molar ratio between natural gas and oxygen for the complete combustion reaction of all the fuels components. so I want to work out how much oxygen I need to natural gas. The ...
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1answer
75 views

Why does microwaving napalm make it nonflammable?

In this video, microwaving napalm made it nonflammable. What caused this to happen? I assume its some sort of chemical reaction, could someone explain? I understand some chemistry, but a not-too-...
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2answers
89 views

What makes a glowing splinter glow and a burning splinter burn

This question bugs me for years since I started learning the oxygen, carbon dioxide and hydrogen tests. I know you can make a glowing splinter burn when doing the oxygen test due to enough oxygen. But ...
3
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1answer
56 views

What is the meaning when it is said “Temperature of an Oxyacetylene Torch is 3500 degrees Celsius”?

I don't think flame is anything but the product at that temperature but I am not sure. What exactly is flame? And I think the correct statement should be that the exothermic reaction here produces ...
4
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3answers
93 views

Controled burn colored fire and safety

I am a martial artist who uses fire weapons in my shows. I am wondering how I can get the flames to be different colors. I've done some research about it, and have found that the salts of some ...
0
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0answers
47 views

What proportion of a combustion engine's output energy comes from the air?

When trying to compare the efficiency and range of electric engines vs gasoline engines, it seemed at first that gasoline had a higher energy density than batteries. But then I realiced that a ...
0
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0answers
14 views

Why does n-butane have a higher enthalpy of combustion than i-butane? [duplicate]

I noticed that n-butane has a higher enthalpy of combustion (-2878 kJ/mol) than i-butane (also known as isobutane or 2-methylpropane) (-2869 kJ/mol). However, I don't see why there is a difference. ...
2
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1answer
117 views

Heat of combustion of stereoisomers of 1-tert-butyl-2,4-dimethylcyclohexane

Which of the compounds below has the smallest heat of combustion? I know that the heat of combustion is indirectly proportional to the stability of a molecule. And here both $\ce{CH3}$ and $\...
3
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39 views

Why branched hydrocarbons are burnt more efficiently(complete & clean combustion)?

Branched and cycled hydrocarbons have usually more octane number than the straight chain ones as their combustion is complete and clean(no residue) and there is no probability of knocking or ...
2
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1answer
53 views

About how much carbon monoxide is produced in these two different reations?

The U.S. Department of Agriculture produces a gas cartridge to poison subterranean rodents. The product is provided as a cardboard tube sealed at one end and then loaded with a mixture of 144.6 grams ...
3
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0answers
26 views

To what degree an N99 active coal filter can protect against products of burning paraffin oil?

I sometimes do firedance and a part of it is waving a stick with burning endings made of kevlar soaked in paraffin oil. I started to be a bit concerned about how healthy is it to inhale lot of ...
12
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2answers
391 views

How can titanium burn in nitrogen?

I was going through the properties of titanium when a certain thing caught my eye: It was the reaction of burning of titanium in nitrogen. I was astonished to read it as I knew that neither is ...
2
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0answers
20 views

Characterization of products of non-stoichiometric combustion

To give some background, I'm looking at this from an aerospace standpoint as to the calculation of the efficiency of a propellant reaction at a given oxidizer-fuel ratio. That efficiency is a ...
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1answer
27 views

Finding the empirical formula [closed]

Combustion of a $0.9835\ \mathrm{g}$ sample of a compound containing carbon, hydrogen and oxygen produced $1.90\ \mathrm{g}$ of carbon dioxide and $1.070\ \mathrm{g}$ of water. What is the empirical ...
0
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0answers
31 views

N2O combustion alternative

Would spraying a sodium permanganate solution into the intake charge of a gasoline engine allow it to burn more fuel? I'm thinking something similar to nitrous oxide.
4
votes
1answer
82 views

At what temperature do complex hydrocarbons become ashes?

When heating a metal tube with polypropelene in it, i found that i still had brittle black foam and flakes in it even though it had been in a blue flame at around 500'C What happens to complex ...
2
votes
1answer
39 views

Number of moles in a chemical equation with an amount of substance given

How many moles of carbon dioxide are there in $20.5~\mathrm{g}$ of oxygen gas given this reaction: $\ce{C15H30 + O2 -> CO2 + H2O}$ So I figured out the balanced equation is $\ce{2C15H30 + 45O2 -&...
0
votes
1answer
26 views

How much CO2 gets free when combusting 6 kg n-heptane (C7H16) [closed]

I am very new to chemistry and have a question to an exercise. It's about combustion (complete oxidation) n-heptane ($\ce{C7H16}$). There were several questions I could answer, for example the ...
3
votes
1answer
382 views

How much CO2 is produced in burning of a candle?

I've been reading this book, page 149. In chapter 15 the following experiment is suggested, Fix a candle in a container. Fill the container with water. Light the candle and then cover it with an ...
2
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0answers
41 views

How to define a flame in numerical combustion?

I am running a CFD simulation (computational fluid dynamics) opposed jet case, where a stream of fresh reactants is opposed to a stream of burnt products. I am looking at the effects of stratification ...
1
vote
1answer
87 views

Incomplete and Complete Combustion [closed]

So I know that complete combustion is a fuel + $\ce{O2}$ which becomes $\ce{CO2 + H2O}$. But what is incomplete combustion? According to the Internet, $\ce{CH4 + O2}$ and $\ce{C6H12O6 + O2}$ are ...
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0answers
122 views

Why does burning wood produce methane and other hydrocarbon chains?

This post kinda helps me understand and it sounds like it has to do with pyrolysis, but I'm having trouble putting the exact reactions together.
0
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2answers
318 views

Why is the smell of car exhaust much stronger in winter?

I noticed that in winter, the smell of cars (to be precise the smell of the exhaust gases) is much stronger in winter. I just can't figure out why. Has this got something to do with the air ...
0
votes
0answers
27 views

What is the standard enthalpy of combustion of maltodextrin?

Writing a lab about yeast metabolism and one metabolite we used was maltodextrin. I cannot find the standard enthalpy of combustion anywhere for this sugar but I can find it for the other sugars we ...
0
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0answers
20 views

Concentration of Oxygen in a Container

I would like to model the reaction between $\ce{CH4}$ and $\ce{O2}$ in a container, but I'm not sure how to determine the initial concentration of the oxygen (in $\Large\rm\frac{mol}{m^3}$), ...
0
votes
1answer
42 views

Why is the sneaky method of smothering a grease fire more effective?

In this demonstration, a grease fire is temporarily extinguished if you put the cover on the pan, but reignites as soon as you take the cover off. However, if you slowly slide the cover across the ...