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Highest Boiling Point

Discussion in 'PCAT Discussions' started by saeghe2000, Aug 18, 2015.

  1. saeghe2000

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    Hi, Can somebody explain this question?

    Which of the following would have the highest boiling point?
    A)NaOH B)CaCl2 C) NH3 D)HCl

    According to Dr collins’ chemistry section the correct answer is CaCl2 because it is a strong electrolyte and can produce 3 ions.

    However, I think the correct answer is NH3 because it is able to have H-bonds.
     
  2. Ph4rmacistJ

    Ph4rmacistJ "We'll have it ready in about an hour"
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    CaCl2 is a strong electrolyte, and generally, stronger electrolytes possess a higher boiling point. Therefore, it's safe to assume that NH3 wouldn't be the correct choice as H-bonds typically wouldn't have a higher boiling point in comparison to that of a compound which is a strong electrolyte.

    I've found a page below for extra clarification:
    https://answers.yahoo.com/question/index?qid=20100522121837AACScJn
     
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  3. Dr.Toothenstein

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    CaCl2=ionic bonds. The stronger the bond the higher the boiling point (makes sense right; stronger force holds it together).

    Order of bond strength which will also corespond to boiling points:

    1) Network Covalent Solids (diamond and quartz (SiO2))
    2) Ionic Compounds
    3) Most Metals
    4) Molecular compounds (H-bonding, then dipole-dipole, then london dispersion)

    NaOH and CaCl2 are your only ionic compounds (CaCl2 having 3 ions). NH3 only has covalent bonds.
     
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  4. PharmHealth_KI

    2+ Year Member

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    Look up "boiling point elevation"
     
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