Is the combustion of fules exothermic or endothermic?
920392
it is exothermic, meaning the combustion reaction releases energy in the form of heat
1163334
Air -- which is primarily nitrogen and oxygen with lots of other gases -- is not flammable or combustible.  It can explode from pressure (such as a ballon that is overfilled), but it cannot explode from combustion by itself.\n\nCombustion requires three things: fuel, oxygen, and heat.  It is a chemical process by which fuel combines chemically with oxygen and releases energy.  This is called oxidation.  If a fuel does not readily combine with oxygen in the presence of heat (or doesn't release a great deal of heat when it does so), it is said to be not combustible (or flammable).  The more energy a fuel releases when it combines with oxygen, the more explosive it is.  Wood burns, but it doesn't (ordinarily) explode.  But TNT explodes. So what air lacks to explode is combustible fuel.  \n\nAlso oxygen is not combustible because it is the component that combines with fuel to make combustion; we call it an oxidizer.  \n\nWhy does the sun burn?  Well in point of fact it does not combust like fire, because it is a nuclear reaction rather than a chemical one.  It's energy is in the form of radiation rather than chemical bonds.  It uses the fusion of hydrogen atoms into helium to release nuclear energy.  So while it is hot, it is not oxidizing, and so is not burning in the way that fire burns.
56607
Depends on the physical properties of the paper, its composition, manufacturing process (residual chemical off gassing), its millage.. etc.\npaper is too generic of a descriptive, think magicians "flash paper" and cardboard.\n as a general rule cellulose (the main component of most "papers") begins outgassing in a Pyrelletic process at around 165-180. At that point it can and will ignite with any external spark.
435509
An Endo-Thermic reaction takes in heat and the Exo-thermic one gives off heat.\n\nExemples:\n\nExothermic processes         \nmaking ice cubes              \nrusting iron                  \n\nEndothermic processes \nmelting ice cubes \ncooking an egg
763107
Reactions can be classified as either exothermic or endothermic.  Exothermic reactions release energy, and cause the surroundings to increase in temperature.  Endothermic reactions absorb energy, and cause the temperature of the surroundings to decrease.
1138895
They are similar, but not exactly the same as exothermic and endothermic as used in chemistry.\n\nExergonic reactions are defined by a negative delta G, that is they have less free energy at the completion of the reaction than at the beginning. An exergonic reaction may require some input of energy (called activation energy) to start the reaction, but will release more energy than is required to start the reaction. \n\nAn endergonic reaction will have a positive delta G, that is it will have more free energy after the reaction than before it starts. \n\nHere is a good website with graphs that explains this:\nhttp://academic.brooklyn.cuny.edu/biology/bio4fv/page/exergon.htm\n\nHere is another website that explains the similarity between exergonic, exothermic, and endergonic, endothermic. \nhttp://www.mansfield.ohio-state.edu/~sabedon/sta5202.htm
930214
solid to gas is endothermic reaction as it absorbs energy\ngas to solid is exothermic as it give off energy
919726
Sodium and Potassium are correct.  They are extremely reactive with water, forming Hydroxides and releasing Hydrogen gas, which is usually ignited from the exothermic heat of the reaction.\n\n2 Na + 2 H2O -> 2 NaOH + H2\n\n2 K + 2H2O -> 2 KOH + H2
462388
A reaction which gives out heat is known as 'exothermic'.\n\nhttp://en.wikipedia.org/wiki/Exothermic\nhttp://en.wikipedia.org/wiki/Exothermic_reaction\n\nA reaction which seems to absorb heat is known as 'Endothermic'\n\nhttp://en.wikipedia.org/wiki/Endothermic\nhttp://en.wikipedia.org/wiki/Endothermic_reaction
812725
When heat is given off, the reaction is exothermic. The sign is negative because energy is given off by the system.
155506
Exothermic reactions are very common.  Most oxidation reactions are exothermic.  This would include rusting iron as well as burning just about any kind of fuel: gas, oil, wax, gasoline or alcohol.  In all of these reactions something is reacting with oxygen and the reaction gives off heat.\nEndothermic reactions are much less common. Commercially available cold packs usually consist of 2 inner containers, one with urea and the other containing ammonium chloride within a plastic bag.  When the containers are broken (usually by bending) the compounds react and absorb heat from the environment.  This makes the bag get cold.
329578
Fire isn't an element. It's a chemical reaction, or more precisely, a combustion reaction. A combustion reaction occurs when there is sufficient heat, fuel, and oxygen. The reaction is this:\n\nthing you're burning + O2 --> CO2 + H2O + other elements
390022
the reaction is exothermic because the resultant solution or products is warmer than the reactants, assuming that it didn't warm up in the enviroment. In addition all neutralisation reactions are exothermic.\n\nThe solutions were mixed rapidly so that the concentration gradiant increases as quickly as possible preventing the reactants absorbing the heat from the reaction before the reaction is finished.  ie the initial rate of reaction being as high as possible.
1184525
Depends on what is being split and where the combustion takes place.  The combustion alone will produce changes of oxygen, hydrogen and any other chemical in the air or around the combustion.  The remaining products will more than like be water, carbon min-oxide, etc.
662425
Heat packs work by utilising exothermic reactions & cold packs work by using endothermic reactions. Meaning that once you start off the reaction, exothermic reactions lose energy & give it off as heat & endothermic reactions require energy & use heat from the surroundings.
908077
A high temperature will only favour those reactions which are endothermic. To be spontaneous, endothermic reactions require there to be an increase in entropy. You can understand this from the Gibbs Free Energy equation deltaG = deltaH - TdeltaS.  deltaG will tend to become negative as T increases.\nHowever, all reactions proceed faster with an increase in temperature, since a greater proportion of molecules have the minimum energy required to react - the activation energy.\nA low temperature will favour exothermic reactions, and will slow down all reactions.\n\nI do think that the question you are trying to answer is not a particularly good one.
97767
Uh, your question is miscategorized\nthe metabolic process is not fire \njust because it shares a single characteristic\ninterestingly the products of hydrocarbon combustion \nare CO2 + H2O\n\nIf you get a 90% efficient furnace it will condense water in the exhaust stack