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Homework Help: When a polar solvent dissolves an ionic substance

  1. Dec 6, 2005 #1
    I can't find the answers to these two questions...could someone help me?

    Describe the process when a polar solvent dissolves an ionic substance.

    Why would SO2 go down in solubility when temperature increases?

    And while I'm thinking of it...my brother brought home his science book and, upon reading over it to help him with his work, I was reminded of just how much better having a textbook is. My Dad is looking into getting one from my public school for me to borrow but I don't think he's going to get one. If he can't, I was going to look into buying one. Does anyone have any suggestions? The only site I've found thus far (I haven't gotten to look around much...I've got homework out the butt to do.) is this one http://www.academicbookservices.com/SearchResults.aspx?ISBN=&Title=&Copyright=05&Publisher=ALL&Category=CHEM&GoToPage=1" [Broken].
    Last edited by a moderator: May 2, 2017
  2. jcsd
  3. Dec 6, 2005 #2


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    Sulfur Dioxide (SO2) is a gas,
    when a gas is dissolved in a liquid, its solubility greatly depends on temperature (and pressure). For example, the carbon dioxide gas dissolved in soda, the drink will stay carbonated a lot loonger in the refrigerator than sitting in the hot sun.
  4. Dec 6, 2005 #3
    I didn't even know a gas could be dissolved in a liquid...:redface:

    How do you read those types of things? I had no clue what SO2 was...what's KNO3 (The three is under the O, not above.)? Could someone tell me how?:smile:
  5. Dec 6, 2005 #4


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    "Cyberschool?" (from your profile) No textbook?

    PM me with the title of the class, a description of the resources you (or your parents) are buying, and any public links to the site, and you get a couple "freebies" --- no remarks about "show us some effort."

    "Describe the process when a polar solvent dissolves an ionic substance. "

    A polar solvent is any solvent with a permanent dipole moment. Water, alcohols, methylene chloride, acetonitrile, the list goes on and on for nearly ever, and the interaction of an electric dipole with the electric field around a charged particle, the ion, be it cation or anion, releases energy.

    Some solvents, water for instance, can exhibit additional interactions through hydrogen bonding: not only are the non-bonding electron pairs on the oxygen atom attracted more strongly to cations than the hydrogens on the water molecule, aligning the water dipole in an O to the cation - H s away from cation direction, but the attraction to the cation allows the orbitals to delocalize the bonding electrons between the O and H in the water molecule, polarizing the O-H bonds further; for small cations, this polarization is sufficient to promote dipole orientation of a second, and sometimes third or more, layer of water molecules about the cations. This behavior is not seen for most anions; fluoride can enhance H-bonding, structure making, but as a rule, there is no permanent shell of water dipoles oriented around anions.

    "Why would SO2 go down in solubility when temperature increases?"

    I was offline typing this, and get back, and see your response to Mr. J.'s hint ---- am I speaking "greek" to you on the first question?
  6. Dec 6, 2005 #5
    Yep, cyber school, no textbooks. I miss 'em.:frown:

    Anyways, I don't know what a dipole is...whatever that is hasn't been mentioned yet.
    Last edited: Dec 6, 2005
  7. Dec 14, 2006 #6
    a year later.... im on that same exact same question in virtural school. (florida)
    Module 3 Lesson 9 of Chemistry I V6
  8. Dec 15, 2006 #7


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    Try going to Wikipedia and searching for the topic "Solvation". It is a pretty good description of what is going on...

    For the gas solubility question, try searching using the phrase "gas solubility temperature dependence". Hint: The ".edu" sites are great places for an .EDUcation!

    Why are you in "cyberschool"?
  9. Dec 15, 2006 #8


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    Bystander has mentioned the arrangement of water molecules around the cations....you should refer to a standard inorganic text which explains the quantum nature of such interactions and while you're at it you may also want to read upon the explanation of what makes up hydrogen bonding (pertaining to the corresponding method of explanation). This step in the whole dissolution process is hydration.

    Your instructor is probably looking for an explanation in terms of Hess' principle (law)....what are the steps in the dissolution of an ionic compound into, say water for example?

    Hint: The first step involves the lattice energy of the ionic compound
    Last edited by a moderator: May 2, 2017
  10. Nov 17, 2009 #9
    Re: Solubility

    I don't understand this either...I am home schooled as well, I need an answer to this question that is simple and sweet....Please help thanks :)
    Last edited by a moderator: May 4, 2017
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