What is exo - thermic and endo - thermic reaction ?
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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
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U CAN MAKE A PROJ ON REACTIONS ON THE FOLLOWING PTS  .\n INTRO OF REACTIONS\nDEFINITION OF A REACTION\n TYPES OF REACTIONS\n THEN, DESCRIBE THEM SEPARATELY
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NH4Cl has an enthalpy of solution of +14.8kJ/mol, meaning the reaction is endothermic.
863957
combustion means oxidation with oxygen. it is done by burning in air.\nHence Mg + heat is combustion reaction. It gives MgO upon reacting with oxygen. But it also reacts with the Nitrogen in the air by giving Mg3N2. That is the side reaction, ofcourse.
812725
When heat is given off, the reaction is exothermic. The sign is negative because energy is given off by the system.
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DH reaction = DH products – DH reactants\n\nExample:  2A + B -- C\nDH = DH C – (2 DH A + DH B)\n\nIf DH is negative: exothermic reaction \nIf DH is positive: endothermic reaction
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Basically what Le Chatelier's Principle is trying to say is that if a system in equilibrium experiences a change, then it will try and counteract that change.\n\nIn this case, the excess heat is the change experienced. To counteract the excess heat, some of it must be absorbed. Thus, the endothermic reaction in which heat is absorbed will occur at a higher rate than the other reaction. \n\nThe endothermic reaction is the forward reaction. (Equilibrium shifts to the right.) Thus, more N2O4 will be converted to NO2 than the other way round, resulting in less brown-coloured N2O4 molecules in the system. Therefore, the intensity of the colour will decrease.\n\n:) hope you find this useful!
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It is exothermic when the rxn. Heat is negative\nConsider Thermite\n\n2Al(s) + Fe2(O3)(s) –> Al2(O3)(s) + 2Fe(l) ∆Hºrxn=-847.6kJ
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2x (G2 + M2 ---> 2GM)      DH=-280.0*2= -560.0 kJ\n2x (L + 2M2 ---> LM4)      DH=-350.0*2= -700.0 kJ\n   (L2G4 ---> 2L + 2 G2)   DH=122.0*(-1)=-122.0 kJ (change sign when flip over)\n\nAdd them together, we'll have:\n2G2 + 2L + 6M2 + L2G4 ---> 4GM + 2LM4 + 2L + 2G2\nthen cancel 2G2 and 2L on both side, we end up with:\nL2G4 + 6M2 ---> 2LM4 + 4GM\nthe enthalpy of this reaction is, therefore the sum of each enthalpies calculated above.\nDH=(-560.0) + (-700.0) + (-122.0)= -1382.0 kJ (exothermic process)\nhope that'll help!
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A precipitate is a solid formed by a reaction. If you mix two chemicals in a test tube and a solid forms it is a precipitate.\n\nendothermic reactions absorb heat and will feel cold to the touch. Exothermic reactions give off heat and will feel warm or hot to the touch.
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Most reactions are exothermic.\nExamples are\n\n1) Combustion of methane (natural gas).\n\n2) Neutralisation of dilute hydrochloric acid and dilute sodium hydroxide.\n\n3) Adding concentrated sulphuric acid to water is highly exothermic\n(gives out a lot of heat).\n\n4) Adding water to anhydrous copper(II) sulphate is exothermic.\nAnhydrous copper(II) sulphate is white.\nAnhydrous is pronounced "an-high-drus"\nAnhydrous means "without water".\n\nAnhydrous copper(II) sulphate is copper(II) sulphate which is completely dry.\nWhen water is added to it, it turns into the familiar hydrated blue crystals.\nHydrated is pronounced "high-dray-tid", it means 'with water'.\nThis is used as a test for water.\n\nIf blue (hydrated) copper(II) sulphate crystals are heated,\nan endothermic reaction occurs, they lose their water,\nturn white and become anhydrous copper(II) sulphate crystals again.\nThe reaction is reversible.\nBlue copper(II) sulphate crystals will also turn white in the presence of  concentrated sulphuric acid.\n\n \n\nFew reactions are endothermic.\nExamples are\n\n1) Photosynthesis.\nChlorophyll is a very clever catalyst,\nwhich allows plants to make sugar from carbon dioxide in the air.\nThe energy needed for the reaction comes from sunlight.\n\n2) The reaction of ethanoic acid with sodium carbonate.\n\n3) Dissolving some salts in water is an endothermic process.\nPotassium chloride and ammonium nitrate\nboth take in energy when they dissolve.\nIf you put a thermometer in the solution as they are dissolving,\nyou will see that the temperature drops.\n\n4) Melting, boiling and evaporation\nare all endothermic processes (not reactions).
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1. This is too big a subject to teach in a few lines.\n2. Enthalpy is the energy of a reaction delta-H (triangle).  The enthalpy of a reaction is the energy given out or absorbed by a chemical reaction.\n\nThis is a simple answer and does not work for large changes in temperature or if a change of state is involved.
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If you are talking about heat energy then it's called an exothermic reaction.\n\nEndothermic reactions are the ones that absorb heat (i.e. they seem to cool things)
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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
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This is a calorimetry problem! There is an equation for it:       \nq = mc(change in temperature)\n\nq = the heat required \nm= mass\nc= specific heat \n\nAlso, write out the reaction and products.
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A thermite reaction is a type of aluminothermic reaction in which aluminium metal is oxidized by the oxide of another metal, most commonly iron oxide.\nVR
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Hi Kitty,\nHere is what, I think, you need.\n\nExothermic, dH < 0, Entropy increases (dS > 0), Reaction is spontaneous and dG < 0\n\nExothermic, dH < 0, Entropy decreases (dS < 0), Reaction is spontaneous only at low temps, if |T dS| < |dH|\n\nEndothermic, dH > 0, Entropy increases (dS > 0), Reaction is spontaneous only  at high temps, if T dS > dH\n\nEndothermic, dH > 0, Entropy decreases (dS < 0), Reaction is not spontaneous, dG > 0