Combustion Definition and 363 Threads

  1. P

    Energy from combustion of element

    So I was reading about lightbulbs... and if I broke the bulb so that oxygen came onto the heated filament, I understand that the tungsten would combust. But how would I figure out how much energy would be given off? Would this cause a fire? I have no chemistry training so be gentle!
  2. R

    Heat transfer inside engine combustion chamber

    Hi, I'm not sure if I've got this in the right section, but I'm hoping someone can point me in the right direction. I'm trying to create a model of what's actually happening during the combustion cycle in an engine and where the energy is going. As the intake valve closes and the piston...
  3. N

    What is the Combustion Formula for Lean C8H18 in Air?

    I am doing a thesis work and I am trying to figure out the amount of C02 and the products in combustion of Air and C8H18. Its known that the engine is operating on lean fuel, but I am having trouble with the reaction formula. This is not my subject. The engine is operating at lambda 1.2 to 1.6...
  4. C

    Thermodynamic equation for combustion in a spark ignition engine

    if i have calorific value of mixture, volume at time of compression, bore diameter, can i know the pressure being exerted on the pistons due to the combustion?
  5. H

    Conversion of Internal Combustion Engine Vehicle to Hydrogen Fuel Cell Vehicle

    I’m from a group that is current working on the theory of a Hydrogen Economy. Our first area of development is the Hydrogen Highway. We are currently seeking help in the form of freelance / work for hire basically engineer(s) that could aid in design and calculations of internal combustion...
  6. G

    Viability of Heat Pipe technology in Internal Combustion Engine Cooling

    Hi there, my first post on this forum and I hope its in the right place ! My question is this, in an exisitng air-cooled motorcycle engine what is the viability of using heat pipe technology to cool exhaust gas temperature? Using heat pipes to remove heat from exhaust valve areas to external...
  7. T

    What is the fastest speed ever recorded, achieved by an internal combustion engine?

    What is the fastest speed ever recorded, achieved by a internal combustion piston engine on a land vehicle, and not an aircraft/propeller? I know that some top-fuel dragsters can exceed 300 MPH.
  8. L

    Gas pressure in internal combustion gasoline engine

    can anyone please tell me what is the gas pressure which applies on piston head just after combustion in cylinder its very urgent and necessary for me to know this please help me
  9. B

    Designing an inline flare gas combustion chamber

    I have built a nice biomass gasifier that produces about 700,000 btu's of heat per hour by burning or flaring the gas that comes out of it. What I want to do is, to flare the gas in an enclosed chamber so I would be able to capture all the exhaust and run it through some heat exchangers for...
  10. S

    Efficiency with a combustion engine

    I've been trying to understand why fuel economy decreases when the engine gets into higher RPMs. That is, if you put the pedal to the metal and quickly accelerate to 40 MPH, your engine operates much less efficiently than if you slowly accelerated to 40 MPH. Here's where it seems the...
  11. J

    Combustion analysis problem? - General Chemistry

    Homework Statement When a sample that is .91 grams is burned in oxygen, it produces 2.073 grams of carbon dioxide, .304 grams of water, and .0944 grams of nitrogen. What is the empirical formula of the compound? The Attempt at a Solution I converted all of the products to moles: CO2: .0471...
  12. E

    Expansion Work in Combustion Reactions: Liquid Water vs. Water Vapor

    Expansion Work -- Still confused. This is more of a general question regarding thermodynamics. If you have a combustion reaction, and it produces either liquid water or water vapor--which case results in higher expansion work? My enthalpy calculations show higher PV work for the reaction with...
  13. D

    Maximizing Mass Airflow in Internal Combustion Engines

    This inquiry is in relation to internal combustion engines. I am trying to figure out how to maximize the mass of air going into my engine. Because the more air that can get into the cylinder, the more power the motor can make. Now I've been researching Bernoulli's Principle and as I understand...
  14. Z

    Calculate the mass of CO2 produced from the complete combustion

    Homework Statement Gasoline consists primarily of octane, C8H18 Calculate the mass of CO2 produced from the complete combustion of 3.79 L (1.00 gallon) of gasoline (assume octane, density = 0.756 g/mL) with excess O2 The Attempt at a Solution The balanced chemical formula would be: 2C8H18 +...
  15. G

    Investigating Combustion of Hydrogen & Boron Compound

    Homework Statement A sample of gaseous substance composed of only hydrogen and boron, underwent combustion with excess oxygen. As a result, all the hydrogen turned into water, and all the boron turned into B2O3. a) find the empirical formula of the substance? b) find the chemical formula...
  16. D

    How Does Temperature Affect NO2 Formation in Combustion?

    Homework Statement We discussed the fact that the formation of some trace gases is thermodynamically unfavorable at low temperature, but more favorable at elevated temperatures. Using the values for delta G and delta H in the notes, calculate the equilibrium partial pressure of NO2 during...
  17. N

    Calculate Heat in Combustion of C4H10(g)

    How much heat, in kilojoules, is evolved in the complete combustion of 1.325 g C4H10(g) at 23.6 degrees Celsius and 738 mmHg? The complete combustion of butane is represented by this equation C4H10(g) + \frac{13}{2} O2(g)\rightarrow 4CO2(g) + 5H2O(l) \DeltaH degrees Celsius = -2877 kJ I...
  18. S

    Molar Enthelpy question with Combustion

    Homework Statement Using the data for the combustion of 3-pentanol calculate the molar enthalpy for the alcohol. Initial mass of alcohol: 27.35g Final mass of alcohol: 26.41g Change in temperature: 21.0C Volume of water: 100.0mL (100.0g) Specific heat capacity of water: 4.18 J/gC...
  19. G

    How does bore/stroke and displacement volume affect an IC engine's power output?

    I am sure someone wrote with great detail on the subject, but i just can't seem to find it in the forums... I want to know about the parameters influencing the performance of an IC engine...obviously, not all parameters, but those we can conviently control specifically...how is bore/stroke...
  20. G

    Combustion mass conservation integral

    Homework Statement integrate [(rs^2)*(rhos)*(us)*(db/dr)=(d/dr)*(r^2)*(rho)*(D)*(db/dr))] rs=radius at surface rhos=density at surface us=velocity at surface r = radius rho = density D= diffusivity b=spalding non-dimensional parameter Homework Equations The Attempt at a...
  21. M

    Required Pressure for 5% Methane-95% Air Combustion to Heat to 853 K

    Homework Statement I want to figure out what pressure would need to be applied onto a 5% methane 95% air mixture to heat it up to the autoignition temp of 853 K. Homework Equations ? The Attempt at a Solution
  22. B

    Combustion when there's left over fuel, what happens to it?

    hi, I'm wondering what happens when you burn a liquid fuel in a combustion chamber, eg. suppose you've got octane (C8H18) and you're using air as the comburent, but the equivalence ratio is less than one, so that not all the octane can get used up... Does the 'left over' octane come out of the...
  23. S

    Combustion Engines: Can Oxygen Be Used?

    Can pure oxygen be used in internal combusion gas or diesel engines? If no, what percentage could be used?
  24. S

    Designing the Best Potato Launcher: Catapults, Compressed Gas, and Combustion

    hello, i was wondering what people here would think the best design type for a potato launcher would be. I looked at catapults, ones that use compressed gas, and combustion. firstly, which would be the easiest to make?
  25. B

    What exactly is heat of combustion? How would I calculate it?

    1. Calculate heat of combustion for butane. Given: mass water- 129.91g mass butane 0.15g old temp- 16.4 degrees C new temp.- 26.7 degrees C 2. Homework Equations 2C4H10 + 3O2 yields 8CO2 + 10H2O 3. The Attempt at a Solution I've tried, but I really have no idea. I only know...
  26. L

    Heat of Combustion Candle Wax Calorimetry

    Homework Statement I'm supposed to find the heat of combustion for candle wax (which was used to boil water in a simple calorimeter), yet I have no clue on how to do it, the lab books at school do not tell anything about the calorimeter's specific heat or give a formula for heat of combustion...
  27. D

    Molar enthelpy of combustion of magnesium

    1. Homework Statement In a calorimeter, a 1.0g sample of magnesium is burned to form MgO. In doing so, 25.5 kJ of energy is released. The molar enthalpy of combustion of magnesium is: a) -0.0392 kJ/mol b) -25.5 kL/mol c) -306.2 kJ/mol d) -620 kJ/mol Homework Equations Q= mc...
  28. S

    Conversion of Enthelpy (Combustion)

    Homework Statement The enthalpy of combustion ∆Ho at t = 25 0C of Benzene (C6H6) is –3169540 kJ/kmol with the H2O in the vapour phase. Calculate the internal energy of combustion ∆Uo in kJ/kg. Calculate also ∆Ho for H2O in the liquid state. Homework Equations ΔH° = ΣΔH°f(products) -...
  29. S

    Combustion Equations: Converting kg to kmol & KJ/Kmol to KJ/Kg

    Hi, I am learning about the above at the moment and was wondering when the reaction equations are given or you have worked these out, are they in kg or kmol. I have looked at mixtures and know how to go between the two when given the ultimate or gravimetric analysis but am unsure when I have...
  30. H

    Calculate Heat of Combustion: Grams, Heat Capacity, Temp Change

    What's the formula for calculating this, given: grams, heat capacity of substance, and temperature change? How about heat combustion per kJ/Mol? Thanks
  31. S

    How Can Hydrocarbon Properties Affect Specific Heat of Combustion?

    specific heat of combustion?? help Homework Statement Chemical Properties of gasoline components Using C5 to C10 hydrocarbons, conduct an experiment to determine the effect of one property of the hydrocarbon on the specific heat of combustion. Homework Equations The Attempt at a...
  32. G

    Internal combustion engine thermal energy loss

    Hello, I know that something around 65% of the potential energy stored in fuel is lossed in an engine through heat. I am trying to find exactly how its lossed, I know some is through piston friction, and some is lossed through the exhost, but I can't find how much is lossed for each...
  33. T

    Climate change due to combustion of fossil fuels

    Has anyone ever researched what contribution, if any, the actual combustion of fossil fuels contributes to global warming? If you added up all the BTU's of energy which have been released in the last few decades, would it add up to something or is it negligible? Of course, all motion due to...
  34. K

    Combustion Catalysts: What are they?

    Something made me think today, are there any catalysts for combustion? I know it depends on the fule (such as hydrocarbons) but I wanted to leave this open to any kind of fule - I was just interested if there are catalysts for combustion and if so, what fule and what are the catalysts...
  35. F

    What are the Mass and Empirical Formula of the Combusted Hydrocarbon?

    2 question I don't get ... =\ any help would be appreciated. I don't even know where to start ... Homework Statement 2. A sample of a hydrocarbon is combusted completely in O2 to produce 21.83 g CO2, 4.47 g H2O and 311 kJ of heat. A) What is the mass of the hydrocarbon sample that was...
  36. S

    Determination of the enthelpy of combustion of Magnesium using Hess's law

    Homework Statement ok so I'm trying to find the change in enthalpy for this reaction: Mg(s) + (1/2)O2--> MgO(s) I've done the lab to find the temperatures of certain reactions, these were: 9.70 Celsius for the reaction Mg(s) + 2HCl(aq)--> MgCl2(aq) + H2(l) 7.60 Celsius for the reaction...
  37. M

    Finding the heat of combustion of magnesium

    Homework Statement Finding the heat of combustion of magnesium.Homework Equations 1.) MgO(s) + 2HCl(aq) → MgCl2(aq) + H2O(l) ∆Hr = 1047.61KJ/mol *This value was found experimentally 2.) Mg(s) + 2HCl(aq) → MgCl2(aq) + H2(g) ∆Hr = 374.36KJ/mol*This value was found experimentally 3.)...
  38. 3

    How to calculate heat of combustion?

    Homework Statement Calculate the heat of combustion per mole of glucose(s), C6H12O6(s). This is the only information given. There is no Hess' law equations or any of the sort. Homework Equations The Attempt at a Solution I already know the answer is roughly -2813kJ/mole but I...
  39. H

    Ways of powering vehicle that is not electricty or combustion.

    As part of my introductory engineering class this year, I have to work with a group to build a small vehicle (no bigger that 2ftx2ftx3ft) that can carry some water up to 250 ft. However, we cannot use any electricity, anything flammable or solid rockets. So right now I'm at a loss as to how to...
  40. S

    View Windows on a Combustion Chamber

    Does anyone have view windows which they installed on their combustion chamber? My team and I are going to install quartz windows on 304 stainless steel, and so far the coefficients of thermal expansion look really different. We are also debating on the shape of the windows. Any hints would...
  41. S

    Is My Balanced Equation for C5H12 Combustion Correct?

    I was given to complete and balance the complete combustion of C5H12 I did this by adding O2 so it would be combusted and got: C5H12 (g) + 8O2 (g) --> 5CO2 (g) +6H2O (g) is this correct? thanks.
  42. F

    Rocket Engine Combustion Chamber Equations

    Good evening all, I was wondering if anyone would be able to point me in the right direction to equations in regards to designing a proper combustion chamber for a rocket engine, as well as for the throat/De Laval nozzle as well. I've looked around and I can't seem to find anything that...
  43. D

    Diesel combustion and gas laws

    Hi all, new guy here. I am trying to understand the laws that govern a diesel motor. I know it compresses air at about 17 to 1 to ignite the fuel and I think that fuel will expand the air in the chamber at about 5 times the volume consistently (from tdc to end of stroke). I am trying to figure...
  44. S

    Trying to Understand the Role of Water in Combustion

    Are these statements fair and true? Water is one of two products of the combustion of hydrogen. Flame is in part a visual manifestation of a collapse in energy state. Heat is a radiant manifestation of a collapse in energy state. The deeper the collapse in energy state the lower the...
  45. D

    Solving Rate of Combustion Problem

    Rate of combustion?? Homework Statement 1. The broader side of a rectangular fiberglass of dimensions 3m x 5m is brought near the flame. The flame is produced upon combustion of gasoline. If the rate of combustion is 0.002 g/s, determine the minimum thickness of the fiberglass so that the...
  46. K

    Specific Heat of CO2 and Methane Combustion

    Hi, Could you please confirm these estimations for me: Knowing that the Energy of Combustion of CH4 is 50.1 KJ/Kg, and that the specific heat for the CO2 at 273.15 K is approximately 0.81 KJ/Kg*K; please, could you confirm that in order to increase the temperature of 1 liter of gas of CO2...
  47. M

    Oxygen enrichment of an internal combustion engine

    Hello I'm exploring the possibility of filtering the induction air of an internal combustion engine through a suitable zeolite to increase its oxygen percentage. I've read the thread on Pressure Swing Adsorbtion and understand that normally air is forced through the zeolite at up to 150kPa...
  48. M

    Calculating Mass Percentage of LSD in Salt Mixture | Combustion Reaction

    Hi, this is my first question, and I'm working on some summer work with a friend and we stumbled upon this problem. Homework Statement A sample of LSD is added to table salt (sodium chloride) given that a 1.00 g sample of a mixture undergoes combustion to reduce 1.20g of CO2, what is the mass...
  49. P

    How Do You Calculate Stoichiometric Coefficients in Natural Gas Combustion?

    I had a question on how to find the stoichimoteric coefficient in combustion reaction contains several types of natural gas. Lets say for example: u start with a natural gas (using moral analysis) 0.865CO2 + a0.08C3H8 + b0.02C3H8 c0.035N2 + d(O2 + 3.76) ------> eCO2 + fH20 + gN2; Using...
  50. E

    Complete Combustion: Higher vs Lower Air Temp

    If i am trying to burn a fuel in air am i right in saying if i have a higher temerature compared to a lower temperature of air, the higher temperature air has more moles of air to burn than the lower temperature air for complete combustion to occur?
Back
Top