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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Is liquid “air” flammable? [duplicate]

I was wondering if liquid "air" (nitrogen, oxygen, and argon mixture) was flammable. Imagine you have a container. This container contains liquid air. The air is in liquid form, and is in direct ...
3
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20 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 ...
32
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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 ...
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1answer
30 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
16 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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22 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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11 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
40 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 ...
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2answers
40 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
46 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 ...
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3answers
55 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 ...
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0answers
15 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 ...
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0answers
13 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. ...
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1answer
71 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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0answers
31 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
40 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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21 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 ...
11
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2answers
173 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
14 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
24 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 ...
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30 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.
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1answer
75 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
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1answer
33 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 ...
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1answer
20 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 ...
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1answer
327 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 ...
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27 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 ...
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1answer
51 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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48 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.
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1answer
143 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 ...
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21 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 ...
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19 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 $\Large\rm\frac{mol}{m^3}$), ...
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1answer
35 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 ...
2
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1answer
37 views

Combustion properties of Dimethyl Ether

I have a C++ code which calculates the combustion thermodynamic variables (temperature, density) and the mass fractions of Dimethyl Ether for different equivalence ratio. I would like to check my ...
2
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22 views

Understanding the energy produced from oxidizing 1 kg of lithium

I am reading the following paper in preperation for a research project on the theoretical energy density of batteries: Lithium - Air Battery: Promise and Challenges and on the second page they ...
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147 views

Are the fumes of burning soap toxic?

A friend of mine has a relative that occasionally burns soap inside their house (for.. some reason?), and they were wondering if the fumes could harm them. There are many kinds of soap, but... ...
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1answer
132 views

Calculate the mass of butane gas that would be needed to heat 724 cm³ of water from an initial temperature of 7.44 °C to 50.7 °C

The thermochemical equation for the combustion of butane is: $$\ce{2C4H10(g) + 13O2(g) -> 8CO2(g) + 10H2O(l)} , \quad\Delta H = -5748 \ \mathrm{kJ\cdot mol^{−1}}$$ So far, I've calculated the heat ...
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1answer
57 views

Calculate the amount of energy released when 500 cm³ of methane gas at STP reacts with excess air according to the equation:

$$\ce{CH4(g) + 2O2(g) -> CO2(g) + 2H2O(l)} \qquad \Delta H = -890\ \mathrm{kJ\ mol^{−1}}$$ I am not totally sure how to work this out. What I did, though, was: $\ce{CH4}$ $M = 16\ ...
3
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1answer
39 views

Does combustion occur more easily at higher oxygen concentrations or just higher oxygen partial pressure?

I saw a trailer for The Martian and started thinking about space flight. I know that spacecraft and spacesuits often operate at low pressure with high oxygen content (near 100% O2 at about 20 kPa), ...
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1answer
46 views

Optimal CFM for kerosene to burn?

I am going to be making a kerosene forge, and I need a refresher on calculus-based chemistry. Given a certain distribution of alkanes, what is the amount of air (21% O$_2$) needed (in cubic feet per ...
2
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50 views

Could the net equations for burning hexene be used as a means of energy source?

$6\ce{CO_2} + 6\ce{H_2O}\xrightarrow{some\;catalyst}9\ce O_2 + \ce{C_6H_{12}}$ $\ce{C_6H_{12}} + 6\ce O_2\to 6\ce{CO_2} + 6\ce H_2$ $6\ce H_2 + 3\ce O_2\to 6\ce{H_2O}$ At one point, I had made a ...
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1answer
53 views

Does the ignition point of flammable substances changes when provided a pure oxygen atmosphere?

I'm wondering if autoignition point decreases for substances when provided higher oxygen concentration.
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16 views

Does constant pressure cooling affect the chemical equilibrium of a mixture?

I am trying to reproduce results of a publication where the opposed jets configuration is studied; one the left is a jet of fresh premixed reactants and on the right a jet of burnt gases. The products ...
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2answers
538 views

Is liquid oxygen non flammable?

Every one knows that liquid oxygen is flammable, but why this tank labeled like this: so is it really liquid oxygen is non flammable?
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50 views

Bond Dissociation vs Hess' Law Enthalpy

I am trying to determine two of the theoretical values for the enthalpy of the combustion of methanol. I have calculated (using Hess' law) that the $ \Delta H_{\mathrm {reaction}}\; = ...
9
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1answer
133 views

What is the oxidation mechanism of gunpowder?

I've been recently looking into fireworks and the chemistry of explosives, and I found out that, amongst others, one of the most important reactions in gunpowder ignition is the oxidation of charcoal ...
5
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1answer
87 views

Paper Towel Soaked with Isopropanol/Water Mixture Burns without Damaging the Paper. Why?

Video: https://www.youtube.com/watch?v=_qFN1hDZwp8 If you choose not to view the video, in the first demonstration a paper towel is soaked in isopropanol. As expected, the paper towel burns. However, ...
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1answer
58 views

Combustion without hydrogen [closed]

Is there any fuels without hydrogen that will combust. My friend believes there might be and do to my experience I have never heard of one. Please explain and if u can show a balanced equation of this ...
5
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2answers
1k views

What causes incomplete combustion?

During the combustion of hydrocarbons, there is a difference between the amounts of carbon or hydrogen that results in incomplete or complete combustion of the material. My question is, besides from ...
2
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59 views

Is white phosphorus really a cool burning fuel?

About 11 months ago, I posted a question on this SE site on cool flames. One of the answers mentioned white phosphorus. However, a few weeks earlier, I played a game called Spec Ops: The Lines, in ...
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1answer
241 views

How to calculate the amount of water produced by the incomplete combustion of propane?

I was wondering if someone could walk me through how to do the following two questions? The complete combustion of pentane has a enthalpy change of $-3509~\mathrm{mol^{-1}}$. Write an equation ...