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    is the enthalpy of the forward reaction exothermic or endothermic? I know to make the reaction occur faster you need to heat it under reflux, but this is not always necessarily the case, as it can proceed with out heat but at a much slower rate. However, when adding heat, does this make the forward reaction endothermic?
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    (Original post by ScreamYourHeartOut)
    is the enthalpy of the forward reaction exothermic or endothermic? I know to make the reaction occur faster you need to heat it under reflux, but this is not always necessarily the case, as it can proceed with out heat but at a much slower rate. However, when adding heat, does this make the forward reaction endothermic?
    endothermic, hence heating under reflux
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    Dunno, ester hydrolysis conditions are also heating under reflux...
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    All heat does is increase the rate of attainment of equilibrium - hence used for both forward and reverse reactions. This doesn't give any clue as to whether the forward reaction is exo or endothermic.
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    Just because you're heating something to reflux doesn't necessarily mean it's endothermic. Remember that kinetics is important as well as the thermodynamics. You can have exothermic reactions which, even though keeping them cold shifts the equilibrium to the right, they would take absolutely forever to reach equilibrium so they need to be heated to increase the rate of reaction. In this case, esterifications using carboxylic acid and alcohol are usually endothermic (not always but I think for A level you can consider it endothermic) so heating has the double effect of increasing rate of reaction and driving the equilibrium to the right.
 
 
 
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