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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Calculating the amount of products , in moles, produced from the internal engine combustion?

I was doing research about the internal combustion engine and i learned that some of the products, after being processed by the catalytic converter, are CO2, water vapour and nitrogen gas (N2). My ...
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19 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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11 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 ...
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1answer
28 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
51 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 ...
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18 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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400 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 ...
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32 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. ...
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2answers
43 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 ...
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2answers
256 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
58 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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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 ...
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33 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
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
134 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 ...
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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 ...
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40 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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37 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
61 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
72 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 ...
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1answer
55 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
72 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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33 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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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. ...
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105 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 ...
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35 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 ...
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49 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 ...
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24 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 ...
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296 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 ...
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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 ...
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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
80 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 ...
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1answer
38 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
24 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
354 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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38 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
82 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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92 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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2answers
299 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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25 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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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 $\Large\rm\frac{mol}{m^3}$), ...
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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 ...
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1answer
38 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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0answers
27 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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219 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
249 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
79 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
64 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
72 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 ...