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Vant Hoff factor problem. General chem 2

  1. Jul 14, 2011 #1
    The van't Hoff factor for KCl is i= 1.85. What is the boiling point of a 0.50 m solution of KCl in water? For water, Kb = 0.51.

    I have the equation which i beleive is (Delta Tb)= Kb x m x i ??

    m= molality.... = .50 m
    Kb is given 0.51
    i is given 1.85

    I have to have 5 sig figs and the answer i get is .47175, but that's not right supposedly. What I'm I doing wrong?
  2. jcsd
  3. Jul 30, 2011 #2
    Are they asking for the increase in the boiling point...or the NEW boiling point? The formula you have gives you the increase but you have to add the number you get to the original boiling point. So here you would add your answer to the boiling point of water. Common mistake people forgetting the last step...
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