The products have more energy than the reactants..does that describe an exothermic reaction?
486588
In chemistry, an exothermic reaction is one that releases heat. It is the opposite of an endothermic reaction. Expressed in a chemical equation:\n   reactants -->product + energy\n\nWhen using a calorimeter, the change in heat of the calorimeter is equal to the opposite of the change in heat of the system. This means that when the solution in which the reaction is taking place gains heat, the reaction is exothermic.\n\nIn an exothermic reaction the total energy absorbed in bond breaking is less than the total energy released in bond making.\n\nThe absolute amount of energy in a chemical system is extremely difficult to measure or calculate. The enthalpy change, ΔH, of a chemical reaction is much easier to measure and calculate. A bomb calorimeter is very suitable for measuring the energy change, ΔH, of a combustion reaction. Measured and calculated ΔH values are related to bond energies by:\n\nΔH = energy used in bond breaking reactions - energy released in bond making products.\n\nFor an exothermic reaction, this gives a negative value for ΔH as a larger value is subtracted from a smaller value. For example, when hydrogen burns:\n\n\nIn Chemistry an endothermic reaction is one in which the products have more energy than the reactants, and thus a net input of energy, usually in the form of heat, is required. Endothermic reactions are often described as reactions that "feel cold", and contrast with exothermic reactions, in which heat is released.\n\nAlthough the process of bond breaking amongst reactants in a chemical process requires an initial input of energy (the activation energy), in the case of an endothermic reaction, the energy released when bonds are formed to create reactants is less than that required to break the bonds in the products; bonding electrons in the products are therefore at a higher energy than the reactants. Heat energy from the material surrounding the reactants is usually what breaks their bonds, so as heat energy is transferred from the surroundings to the reactants, the surroundings get colder. This is often summarized in a chemical equation as follows:\n\nReactants + Energy → Products
341402
Specific heat does not apply to reactions, only actual chemicals.  You are probably thinking of the heat of reaction, or enthalpy.  The change in enthalpy of a reaction (written as delta H, delta as the Greek letter that looks like a little triangle) flips its sign when the reaction is run in the reverse direction.  So a positive delta H value becomes negative when the reaction is run in reverse direction, and a negative delta H value becomes positive.
945103
No as far as I know All Cumbustion reactions are exothermic
390030
heat mainly - the energy is wasted in the form of heat instead of transferable energy
970108
it will speed up the reaction since the heat rises the temperature.\nit will also decompose a compound to its elements--decomposition reaction.
959876
a) the hydration energy is greater because the temp decreases. When you go from a low potential energy substance to a high potential energy substance the temp of solution will decrease.\n\nb) the solubilty will increase because energy is on the reactant side of the equation. (the reaction is endothermic and requires energy to occur)
196178
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
732299
The sign there is a chemical reaction is the fact there is heat being released.  Evidently, the reactant have more energy, because they are able to release that energy in the form of heat.
485922
the minimum amount of energy required to start a reaction
526499
Well, if you get something with the second to lowest potential energy in the world, that energy can go to the lowest potential energy thing in the world and that's it.  Otherthan that, no.  And there's nothing inherent in the material, unless you're talking about chemical reactions, in which case, I just don't know what those two things are.  I hope that's clear.
49208
The types of reactions are endothermic and exothermic.Also there are the types like reversible and irreversible.And according to me there are four types of reactions:-\n1) Displacement Reactions\n2) Combination Reactions\n3) Decomposition Reactions  &\n4) Double Decomposition Reactions.
829949
energy input: reaction requires energy to take place - endothermic\nenergy output: reaction gives off energy when it takes place - exothermic
20960
Many chemical reactions release energy in the form of heat, light, or sound. These are exothermic reactions. Exothermic reactions may occur spontaneously and result in higher randomness or entropy (ÄS > 0) of the system. They are denoted by a negative heat flow (heat is lost to the surroundings) and decrease in enthalpy (ÄH < 0). In the lab, exothermic reactions produce heat or may even be explosive. \nThere are other chemical reactions that must absorb energy in order to proceed. These are endothermic reactions. Endothermic reactions cannot occur spontaneously. Work must be done in order to get these reactions to occur. When endothermic reactions absorb energy, a temperature drop is measured during the reaction. Endothermic reactions are characterized by positive heat flow (into the reaction) and an increase in enthalpy (+ÄH). \n\nExamples of Endothermic and Exothermic Processes \n\nPhotosynthesis is an example of an endothermic chemical reaction. \nIn this process, plants use the energy from the sun to convert carbon dioxide and water into glucose and oxygen. This reaction requires 15MJ of energy (sunlight) for every kilogram of glucose that is produced: \nsunlight + 6CO2(g) + H2O(l) = C6H12O6(aq) + 6O2(g) \n\nAn example of an exothermic reaction is the mixture of sodium and chlorine to yield table salt. This reaction produces 411 kJ of energy for each mole of salt that is produced:\n\nNa(s) + 0.5Cl2(s) = NaCl(s) \n\nEndothermic reactions take in energy from their surroundings\n\nDissolution of salt is endothermic because it takes energy from its surroundings not much but some.\n\nAs far as all salt types that is hard to say and you would have to do an experiment to find that out.
92261
1.  Heat speeds up a reaction by increasing vibrations and energy of the reactants.\n\n2.  Concentration speeds us a reaction by making more reactants available in a unit volume.\n\n3.  Catylists speed up a reaction (without being used up) by allowing reactants to come into closer proximity.\n\n4.  Increased surface area (by grinding, etc.) speeds up reactions by making more reactants exposed to reaction.
758969
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.
607425
Yes, provided the conditions are right. For example if the reaction\n\nA + B -> c + d\n\nis exothermic, the reaction in reverse will be endothermic, i.e. you will have to supply the heat.
96040
The phrasing is wierd, shouldn't there be a from between flow and the?\n\nIf two substances have different _temperatures_, heat will flow [from] the hotter [substance] to the colder [substance].\n\nThis is because heat, at the molecular level, is related to how fast molecules are moving. When a substance whose molecules are moving faster comes in contact with an object that's moving slower, the faster molecules will collide with the slower molecules of the second object, slowing down the faster molecules while speeding up the slower ones. Thus, heat (average kinetic energy of a substance) is transferred from the hotter substance to the colder one.