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Do you know Thermochemistry ?

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  • Do you know Thermochemistry ?

    Thermochemistry is the study of the heat released or absorbed as a result of chemical reactions. It is a branch of thermodynamics and is utilized by a wide range of scientists and engineers. For example, biochemists use thermochemistry to understand bioenergetics, whereas chemical engineers apply thermochemistry to design manufacturing plants. Chemical reactions involve the conversion of a set of substances collectively referred to as "reactants" to a set of substances collectively referred to as "products." In the following balanced chemical reaction the reactants are gaseous methane, CH4(g), and gaseous molecular oxygen, O2(g), and the products are gaseous carbon dioxide, CO2(g), and liquid water H2O(l):
    CH4(g) + 2 O2(g) → CO2(g) + 2 H2O(l) (1)

    Reactions in which a fuel combines with oxygen to produce water and carbon dioxide are called combustion reactions. Because natural gas consists primarily of methane, it is expected that reaction (1) will liberate heat. Reactions that liberate heat are termed exothermic reactions, and reactions that absorb heat aretermed endothermic reactions.

    The heat associated with a chemical reaction depends on the pressure and temperature at which the reaction is carried out. All thermochemical data presented here are for reactions carried out under standard conditions, which are a temperature of 298 K (24.85C) and an applied pressure of one bar. The quantity of heat released in a
    reaction depends on the amount of material undergoing reaction. The chemical formulas that appear in a reaction each represent 1 mole (see article on "Mole Concept") of material; for example, the symbol CH4 stands for 1 mole of methane having a mass of 16 grams (0.56 ounces), and the 2 O2(g) tells us that 2 moles of oxygen are required. Thermochemistry also depends on the physical state of the reactants and products. For example, the heat liberated in equation (1) is 890 kilojoules (kJ); if, however, water in the gas phase is formed, H2O(g), the heat
    released is only 802 kJ. Reversing a reaction like (l), which liberates heat, yields a reaction wherein heat must be supplied for the reaction to occur. The following reaction absorbs 890 kJ.
    CO2(g) + 2 H2O(l) → CH4(g) + 2 O2(g) (2)

  • #2
    I wonder, based on what I remember from high school chemistry, if, in some homeopathic cases where certain symptoms in which heat relieves, if it might be possible that these symptoms may ,even if only localized, indicate a slowness in there development because the biochemical activity {I realize that this type of chemistry is much more complex than that,in a lab.}needs more heat applied to speed up certain reactions in there development because of under reactions caused by a distortion in ind. vital force.{relative Weakness in reaction} Other case , where cold ameliorates COLD could indicate an Over reaction in vital force where cold is needed to slow down reaction. Analogically similar to the obvious over reaction where , when most people ars stung by a bee, recover without manifesting the severe allergic reaction, often moving toward anaphylactic shock, displayed by a minority. In summation , manifesting in one ind.exothermic reaction, in another endothermic reaction. Hope I've made some sense in this speculation. Best regards,Fredric.
    Last edited by Fredric; 15th May 2009, 05:13 PM. Reason: left out a word

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    • #3
      Originally posted by chenhongxia View Post
      Thermochemistry is the study of the heat released or absorbed as a result of chemical reactions. It is a branch of thermodynamics and is utilized by a wide range of scientists and engineers. For example, biochemists use thermochemistry to understand bioenergetics, whereas chemical engineers apply thermochemistry to design manufacturing plants. Chemical reactions involve the conversion of a set of substances collectively referred to as "reactants" to a set of substances collectively referred to as "products." In the following balanced chemical reaction the reactants are gaseous methane, CH4(g), and gaseous molecular oxygen, O2(g), and the products are gaseous carbon dioxide, CO2(g), and liquid water H2O(l):
      CH4(g) + 2 O2(g) → CO2(g) + 2 H2O(l) (1)

      Reactions in which a fuel combines with oxygen to produce water and carbon dioxide are called combustion reactions. Because natural gas consists primarily of methane, it is expected that reaction (1) will liberate heat. Reactions that liberate heat are termed exothermic reactions, and reactions that absorb heat aretermed endothermic reactions.

      The heat associated with a chemical reaction depends on the pressure and temperature at which the reaction is carried out. All thermochemical data presented here are for reactions carried out under standard conditions, which are a temperature of 298 K (24.85C) and an applied pressure of one bar. The quantity of heat released in a
      reaction depends on the amount of material undergoing reaction. The chemical formulas that appear in a reaction each represent 1 mole (see article on "Mole Concept") of material; for example, the symbol CH4 stands for 1 mole of methane having a mass of 16 grams (0.56 ounces), and the 2 O2(g) tells us that 2 moles of oxygen are required. Thermochemistry also depends on the physical state of the reactants and products. For example, the heat liberated in equation (1) is 890 kilojoules (kJ); if, however, water in the gas phase is formed, H2O(g), the heat
      released is only 802 kJ. Reversing a reaction like (l), which liberates heat, yields a reaction wherein heat must be supplied for the reaction to occur. The following reaction absorbs 890 kJ.
      CO2(g) + 2 H2O(l) → CH4(g) + 2 O2(g) (2)
      What bearing does this have on homeopathy?

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      • #4
        Originally posted by moopet View Post
        What bearing does this have on homeopathy?
        None whatsoever. If it had, we would not be discussing whether anything was in the remedies; we would simply measure it.

        Hans
        You have a right to your own opinion, but not to your own facts.

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