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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697 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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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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1answer
399 views

Why does microwaving napalm make it nonflammable?

In this video, microwaving napalm made it nonflammable. What caused this to happen? I assume it was some sort of chemical reaction. Could someone explain? I understand some chemistry, but a not-too-...
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1answer
121 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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1answer
1k views

Can we do combustion caused by limited supply of air in a lab? How?

For example Ethyne in combustion by limited supply of air $$ \ce{ 2C2H2 + 3O2 ->[\Delta] 2CO2 + 2H2O + 2C } $$ vs. $$ \ce{ 2C2H2 + 5O2 -> 4CO2 + 2H2O + Energy } $$ What are the limits ...
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How to determine the empirical formula for terephthalic acid from its combustion products?

Terephthalic acid is an important chemical used in the manufacture of polyesters and plasticisers. It contains only $\ce{C}$, $\ce{H}$, and $\ce{O}$. In one experiment, $0.4953~\mathrm{g}$ of the acid ...
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1answer
159 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
4k 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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2answers
7k views

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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2answers
9k 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
99 views

Ventilating combustion byproducts in water heaters

I'm designing a system that will heat water by burning natural gas which is commonly available. I would like to have a slow flame because water will need to reach $\mathrm{70^\circ C}$ and stay there. ...
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1answer
510 views

Vapour pressure of a solute obtained during eudiometric analysis of methane combustion

Problem In a eudiometer $\pu{14 ml}$ of $\ce{CH4}$ and $\pu{38.5 ml}$ of $\ce{O2}$ was introduced. After explosion and cooling to initial temperature ($\pu{23 °C}$) the volume of eudiometer was found ...
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0answers
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What is the coolest known flame? [duplicate]

Inspired by this youtube demonstration by ChemicalForce, I'm prompted to ask what is the coldest possible flame. What the video seems to show is phosphorus vapour in an inert gas being blown into air. ...
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0answers
750 views

Equation of combustion of heavy fuel oil (HFO)

We are researching the use of heavy fuel oil (HFO) on ship vessels, but are having trouble finding the equation of the chemical combustion process of HFO. I understand that it contains long chains of ...
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0answers
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How do fuel/oxidizer combustion mechanics change when the constituents are supercritical?

The problem to solve is this: I want to create a heat generator [or heat absorber] that functions at atmospheric pressure to the pressure at the bottom of the sea. It will be used to drive a Stirling ...
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0answers
521 views

Calculate work done by burning benzoic acid exposed to the free air

I'm self-studying and can't solve this problem in Ball's Physical Chemistry. Now, the errata shows that the answer in the book is not correct; still, I can not make sense of it. $(2.55)$ Benzoic acid,...
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44 views

Magnesium combustion heat [closed]

When you are going to burn magnesium you need to wait a few seconds before it actually starts to burn. To get to this point it needs a certain amount of energy/heat. How much does it need?
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90 views

In a jet or internal combustion engine that burns hydrogen as a fuel, what would happen if you replaced the hydrogen with deuterium? [closed]

Would it increase the power of the jet engine due to heavier atoms being exhausted out the back? For the same reason would it slow down an internal combustion engine?
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0answers
67 views

Why won't my propane combust when I spark it?

I need to run an experiment and have some pretty basic questions. I'm trying to get combustion of propane in a controlled environment. I understand that that looks like this: $$\ce{C3H8 + 5O2 -> ...
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0answers
142 views

Is it true that when hydrogen reacts with oxygen to form water, that if first forms an hydroxyl radical? [closed]

When I took chemistry in high school, the inevitable question as to whether or not water has a chemical name came up. Our instructor said no, but if it did it ought to be called hydrogen hydroxide. ...
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0answers
60 views

How much energy can be produced by burning sewage gas?

I am an eighth grader. I need to make a science project on the production of electricity from sewage. I know that almost sixty percent of sewage gas is Methane and most of the other constituents are ...
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0answers
106 views

Chile 2017, One of the Largest Fires in South America: Wood Ash Derivates for Industrial Applications [closed]

Hi: We're a group of people who wants to help people, domestic animals and wildlife recovering from this fire. Summary: We're having in Chile one of the largest fires in South American history. More ...
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0answers
130 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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0answers
63 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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0answers
80 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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0answers
625 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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0answers
3k views

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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2answers
271 views

Will mixing hydrogen and oxygen without a spark result in combustion? [duplicate]

I plan to do the electrolysis of dilute sulphuric acid. This will produce hydrogen gas and oxygen gas at the anodes. I do not plan to collect these gases, but to simply let it form and release into ...
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3answers
2k views

Are all volatile liquids combustible?

I realized that liquids like petrol, kerosene and even perfumes are combustible when they are volatile. Could that be the reason why water is not combustible is because it is not volatile? Are ...
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2answers
61 views

Combustion and oxidation [closed]

What is the difference between combusting and oxidizing? Oxidation of alcohols leads to formation of aldehydes and carboxylic acid whereas the combustion of alcohols leads to the formation of carbon ...
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3answers
160 views

Combustion analysis methodology question

I am questioning the answer key of an exam question my chemistry professor has given, because I think there is a flaw in the methodology of the exam answer. I have worked out my solution using my ...
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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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2answers
10k views

How can metals like magnesium and sodium burn underwater?

Any websites I have found have conflicting answers. One said that they don't actually burn underwater, rather they separate hydrogen from oxygen and burn at the surface. Another actually said that ...
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3answers
861 views

Calculating standard combustion enthalpy of dodecane from that of heptane & octane

These are the problem from UKChO-2015. Given the standard enthalpy changes of combustion ($\Delta_\mathrm{c}H$) for heptane ($n = 7$) and octane ($n = 8$) are $-4816$ and $-5470~\mathrm{kJ~mol^{-1}}...
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2answers
840 views

Spectrometry in Chemistry & Flame Test Lab

Question 1: You currently see two colors that are two similar (dark yellow and orange) in a flame test lab. And also you have a hard time differentiating the colors, what is an alternative to ...
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2answers
12k views

Air contains 20 % O2 by volume. How many cm³ of air will be required for oxidation of 100 cm³ of acetylene?

Air contains 20 % $\ce{O2}$ by volume. How many cm³ of air will be required for oxidation of 100 cm³ of acetylene? (a) 1064 cm³ (b) 212.8 cm³ (c) 500 cm³ (d) 1250 cm³ Answer: (d) My solution: ...
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1answer
43 views

Why doesn't this question violate the conservation of mass?

Combustion of of $0.255 \space g$ of isopropyl alcohol produces $0.561 \space g$ of $\ce{CO_2}$ and $0.306 \space g$ of $\ce{H_2O}$. Determine the emperical formula of isopropyl alcohol. I'm not ...
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1answer
115 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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1answer
128 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 ...
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1answer
233 views

Water evaporation from calorimeter giving less exothermic enthalpy value?

To find the enthalpy change of combustion for an alcohol, you use a calorimeter filled with water and heat it by burning an alcohol. I was told that usually experimental values for the enthalpy ...
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2answers
199 views

Why polyethylene (PE), wool (polyamide) and cotton (cellulose) burnt with different smells, while they just product CO2 (and N2)?

Both PE and cotton produce CO2, but they distinctly have different smells while being burnt (Burning PE has smell of candle wax, while burning cotton’s smell is like burning leaves). Wool produces CO2 ...
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2answers
76 views

Why doesn't natural gas combustion release only one-sixth as much carbon dioxide as coal burning?

Burning hydrogen releases a little more energy than burning carbon, correct? And methane is CH4, but coal is mostly C, correct? So shouldn't burning pure carbon release five times the CO2 (Assuming ...
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1answer
77 views

Complete Combustion of Inorganic, Hydrogen Containing Covalent Compounds in the Atmosphere

From what I've seen in alkanes, their complete combustion creates carbon dioxide, which has carbon in its highest possible oxidation state. I've been wondering what complete combustion would look ...
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1answer
147 views

Combustion of Rocket-Candy with Fe2O3

We know from Wikipedia that the combustion of rocket candy follow this equation : $\ce{48 KNO3 + 5 C12H22O11 → 55 H2O + 36 CO2 + 24 K2CO3 + 24 N2}$ We can add small quantity of iron (III) oxide ($\...
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1answer
63 views

Usage of ammonia as odorant in fuel gases

Usually, thiols such as ethanethiol are added to fuel gases to warn the user of a leak. Why is a few percent of ammonia not used instead? Ammonia is flammable so it will burn to nitrogen and water in ...
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1answer
155 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
208 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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1answer
357 views

test tube cracked when added glycerin to potassium permanganate

I am not expert in chemistry.I learned about combustion in reaction when added glycerine to potassium permagnet.I tried it at home, I took potassium permagnet in test tube and when I added glycerine ...
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1answer
124 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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2answers
300 views

Rate law of the reaction of propane with oxygen

In class, I have a demonstration where I light a bubble filled with propane. As I add oxygen, the bubbles combust faster and more quickly. I have already balanced out the chemical reaction like so: $$...

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