Is there any difference between Miscible and Soluble?

  1. Are there any differences between the terms Miscible and Soluble? I am kind of confuse between these two terms. Are they interchangeable? Thank you!
     
  2. jcsd
  3. chemisttree

    chemisttree 3,721
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    Miscible generally refers to two liquids. Soluble generally refers to a property of a solid in a liquid. Otherwise, spelling is the only difference.
     
  4. maybe i'm wrong, but, when a substance dissolves, there is an energy change, e.g for NaCl to dissolve in water at rtp, the Delta H is +5kJ/mol

    but for miscible substance i'm pretty sure there's no energy change... because the molecules only get between each other....
     
  5. According to me, miscible word is used only for 2 or more liquids.
    Surely the 2 phenonmena have + entropy.
    Khshal says there's no change in energy in miscible substances. I am not very sure. But some liquids give off heat when being mixed.
     
  6. chemisttree

    chemisttree 3,721
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    There is indeed heat of mixing for two or more miscible liquids. For miscible liquids, entropy and enthalpy effects are not usually as high as with solids dissolving into liquids. Haiha is correct... some liquids do give off heat when mixed. Some absorb heat when mixed. Heat absorption by mixing two liquids (one saturated salt (LIBr) the other distilled water) is the basis of natural gas and solar-powered absorptive air conditioning.
     
  7. some substances dissociate when mixed and create heat and others go through an endothermic reaction like ammonium nitrate and water, some you mix and expect to be more and there is less (mix 1 ml with 1ml and get 1.5ml)like isopropyl alcohol and water, that is miscible
    the only diffirence i know between miscible and soluble is the person saing it because my science teacher didn't use the word miscible very often, only when we were taking notes and we had to know what it ment, even when we were doing labs. She would refer to liquids being soluble in a liquid.
     
  8. chemisttree provided an easy understanding to it. miscible simply means two liquids mixing together while soluble is when a solid added in solution and dissolves. i hope its right..
     
  9. Miscible is said when two liquids can be mixed with eachother. Water and oil are not miscible but water and ethanol are miscible.

    Soluble is what you call a substance when it can dissolve into a solvent.

    Both systems entail a change in entropy and as such will cause the exchange of energy with the surroundings.
     
  10. I think

    To my best understanding that the words miscible and soluble that our friend mentioned here is talking about the physical properties of the solute and the solvent.
    as I know that when we mix substances together they are aither miscible or unmiscible. However, "soluble" refers to dissolving of a solid substance which we call solut into a large amount of solvent which is another substance. There are of course that energy require because of entropy of the system have changed when the solute is dissolve. Howeve, physically, the solubility of a solid is depend on its solubility constant Ksp.
    I think that we hav talk so far into the energy concept of a physical problem.
    My reply is utmost to my knowledge, but I am sure that comment is necessary. Please feel free to comment so we all can study more about science.
    Best regard guys!
     
  11. Thank you for the explainations :) That really helps!
     
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