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B Instantaneous Reactions

  1. Jul 6, 2017 #1
    Do instantaneous Reactions happen at infinite speed?
     
  2. jcsd
  3. Jul 6, 2017 #2

    phinds

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    Define "instantaneous reaction"
     
  4. Jul 7, 2017 #3
    E.g. when an acid reacts with a base...
     
  5. Jul 7, 2017 #4

    jbriggs444

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    What makes you call that "instantaneous"?

    If one pours an acid into a base, time will elapse before all the acid is poured in. And time will elapse while the acid that is poured in mixes with the base.
     
  6. Jul 7, 2017 #5
    Lol... I mean when an acid molecule reacts with a base molecule...
     
  7. Jul 7, 2017 #6

    phinds

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    Well, if that is your definition of "instantaneous reaction" (a definition which makes no sense to me) then obviously it does not happen with infinite speed. Since your definition of "instantaneous reaction" is so wrong, perhaps you also have something in mind for "infinite speed" that is also different than what is normally mean by that phrase.
     
  8. Jul 7, 2017 #7
    Why don't you provide an exact definition of an instantaneous reaction..
     
  9. Jul 7, 2017 #8

    phinds

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    That is not how it works here. If YOU use a term then YOU are responsible for stating your understanding of what it means, preferably with citations if necessary. You can't just throw out some term and then expect me to define it.
     
  10. Jul 7, 2017 #9

    jbriggs444

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    One reference in this vein is "The Endochronic Properties of Resublimated Thiotimoline, I Asimov, Astounding SF, March 1948".

    Tongue firmly in cheek, but Asimov does dot his i's and cross his t's, providing a relevant definition of reaction speed...

    Where the physical characteristics of two given compounds - particularly the degree of subdivision of the material - are equal, then the time of solution - expressed in seconds per gram of material per milli-liter of solvent [...]
     
    Last edited: Jul 7, 2017
  11. Jul 7, 2017 #10

    russ_watters

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    Also, what do you mean by "speed"? I know it as distance over time. Where's your distance? Or do you mean reaction rate (moles per second or something)?
     
  12. Jul 7, 2017 #11
    Even for the most rapid chemical reactions, there is chemical kinetics involved. So, no, chemical reactions do not occur instantaneously.
     
  13. Jul 7, 2017 #12
    In an attempt to maybe salvage an interesting discussion in this thread, what could be interested to talk about is for example the change in an electron's binding when two atoms merge into a molecule, and thus an electron is actually part of both shells. I guess in the end the answer is "the wave equation evolves from one state to another", but what are the time scales involved, and how does this evolution look like?
     
  14. Jul 7, 2017 #13
    Thanks everybody for the answers...

    Actually, I think I was not able to express myself properly nor was able to provide a good example...

    I want to say that 'when there is/are sufficient cause(s), the effect is bound to happen necessarily... Isn't this instantaneous?

    For example in an entangled pair, a change in one particle is instantaneously reflected in the other... Isn't this infinite speed?

    Can anybody provide me good examples of instantaneous Reactions?

    Thanks
     
  15. Jul 7, 2017 #14
    Ok, this is called a spontaneous process not an instantaneous process.
    This is quantum mechanics not chemistry. Regardless, quantum entanglement doesn't actually transmit information (as far as we know), so nothing is actually travelling at any speed.
    A spontaneous reaction happens when the change in the Gibbs free energy of a system is negative and is dependent on the change in enthalpy, entropy, and temperature.

    Check out this site for more on this topic. http://www.chem.tamu.edu/class/fyp/stone/tutorialnotefiles/thermo/gibbs.htm
     
  16. Jul 7, 2017 #15
    Do you want to say that there is nothing like 'instantaneous reaction'...
     
  17. Jul 7, 2017 #16
    Well, no process can really happen instantaneously.
     
  18. Jul 7, 2017 #17
    @Deepak K Kapur , I find your line of questioning a bit bewildering. In your OP you had already somewhat answered your own question, in that anything truly "instantaneous" would imply infinite speeds. I am assuming here you are aware of Einstein's relativity and its statement that nothing can go faster than the speed of light. As such, it is evident that no reaction can be truly instantaneous.
     
  19. Jul 7, 2017 #18

    phinds

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    I think your problem is that you are equating speed inversely to motion but there is no "speed" involved in entanglement in the same sense as speed is involved in motion. You are trying to go from zero time to infinite speed but that implies you are thinking of r=d/t which is a motion equation and doesn't apply. Stick with zero time and you're ok (*)

    * technically we don't know for sure that it is zero time but if it's not zero it WAY closer than anything we're ever likely to be able to measure.
     
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