Chemistry 122:Energetics of Solution Formation

Chemistry 122:Energetics of Solution Formation - Chemistry...

Info icon This preview shows pages 1–2. Sign up to view the full content.

Chemistry 122 1/27/2014 Energetics of Solution Formation The solution process is accompanied by changes in enthalpy. Example: when NaCl dissolves in H 2 O, the process is slightly endothermic ΔH sol = 3.9 kJ/mol. Three processes affect the energetics of solution: 1. Separation of solute particles ( ΔH solute ) 2. Separation of solvent particles ( ΔH solvent ), 3. New interactions between solute and solvent ( ΔH mix ). The enthalpy change of the overall process depends on H for each of these steps. Recall Hess’s Law: ΔH sol = ΔH solute + ΔH solvent + ΔH mix The formation of a solution can be either exothermic or endothermic ( see next slide). *When you break in interaction, you need energy* The dropping of the kinetic energy means lower/less heat Just because a substance disappears when it comes in contact with a solvent, it doesn’t mean the substance dissolved. It may have reacted. Dissolution is a physical change—you can get back the original solute by evaporating the solvent.
Image of page 1

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern