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Boiling Point: Hydrogen Bonding vs. DelT = imK

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regeneration

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Hi,

I'm looking at number 11 in BR Chemistry Chapter 4.

The question is basically comparing the boiling point of 0.1M HCL in water and 0.1M HCLO in water. Since HCL adds the Cl- ion to solution, delta t = imk would predict that the boiling point is elevated. However, I also thought that HCLO would be able to hydrogen bond to the water, which would elevate its boiling point.

The answer given is that HCL has a higher boiling point. Can someone explain the magnitudes by which each is changing the boiling point or if I'm getting confused?
 

LoLCareerGoals

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HCL dissociates completely into H+ and CL-, while HCLO a weak acid will not. So when you do the computation for deltaT, concentration of the solute ions will be higher for the HCL then for only paritally dissociating HCLO. This is sort of bottom line response.

Now all that other stuff about H-bonds is already incorporated into dissociation constants. Frankly I don't exactly know why HCLO does not dissolve as well as HCL, but I know it doesn't and that's all I need to know to answer this question. You are starting to get into the "whys" of dissociation constants, which is probably deeper than you need to go when you can just memorize that oxy-chloro acids are weak till we get to HCLO3 and HCLO4 range.
 
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