Why don't endothermic reactions violate the 2nd Law of Thermodynamics?

well, it is possible to decrease entropy in a reaction. if i cool some water down and it freezes, then my highly disordered liquid forms a highly ordered crystal, and the entropy of my water is lower.

but, you have to consider the statement of the second law, which is that the entropy of the *universe* is always increasing. it costs you some energy to cool your water down - you have to run a freezer or something - and the production of this energy at some other point in the process comes with an increase in entropy that is greater than the decrease you get from freezing.

as for an endothermic reaction, i am not sure which reaction you are speaking of. so i will give a simple example of an endothermic reaction:

H2O (l) -> H2O (g)

when water evaporates, it cools its container and draws heat in. however, this is accompanied by an increase in the entropy, since you go from a more-ordered (liquid) state to a less-ordered (gaseous) state.

typically, an endothermic reaction will involve some kind of phase change, where for example you mix two solids together and you end up with a liquid and a solid. here is an example of that:

http://jchemed.chem.wisc.edu/JCESoft/CCA/CCA3/MAIN...

so, the random thermal energy is converted into useful ordered bond energy - this is a decrease in entropy. but it comes at the expense of breaking *other* bonds and using their energy, and an overall increase in entropy of the system.

It relatively would not have something to do with evolution. Even by way of no longer getting it you nevertheless understand greater approximately it than creationists. The 2d regulation relatively states that for the time of a closed equipment the quantity of available capability is fastened and, mutually because it isn't any longer destroyed, it does develop into greater ineffective. that's the comparable reason perpetual action machines do no longer and could never artwork. Their "argument" is that length evolution is relatively an boost in business enterprise, this violates the 2d regulation and is for this reason impossible. that's of course nonsense you have probable already observed it. precise now, you're physique is attempting to attain a state of thermal equilibrium with the exterior atmosphere (it is the 2d regulation at artwork). project is, a physique in equilibrium with the exterior atmosphere is a state regularly prevalent as "ineffective". You guard a differential between you and the exterior atmosphere because you intake capability. You eat, you breathe etc. you're no longer a closed equipment you radiate physique warmth and do mechanical artwork (you progression around) yet you're capability reserves are continuously resupplied. sickness can develop into order given an expenditure of capability. The Earth, and evolution, are the comparable they continuously get carry of capability from the solar. The creationist argument might in straight forward terms carry if we've been in some style of bubble that sealed us off from something of the universe.

Because you have to consider the entire system that the reaction is taking place in...and the fact that energy comes in many forms