Mistake in the Examkrackers book?

[thechairman]

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Hi, I am using the EK complete study package to prepare for the MCATS. In the chemistry book, lecture 4.6 on vapor pressure, it says that :

"above the melting point, the liquid vapor pressure is greater than the solid vapor pressure, below the melting point, the solid vapor pressure is greater than the liquid vapor pressure"

this is a mistake right? because in the gen chem textbooks, it is the other way around.

i was wondering, if there was any other mistakes that other people have seen in the EK books. Is there a thread on this already?

 

[jochi1543]

I don't know if it's a mistake or not, BUT if you go to the Examkracker website (forgot the URL, just Google) and then register for their forums, you have full access to an official errata forum - they will be listing all the mistakes in every edition and giving the corrections there.

 

[FlowLimited]

Hi, I am using the EK complete study package to prepare for the MCATS. In the chemistry book, lecture 4.6 on vapor pressure, it says that :

"above the melting point, the liquid vapor pressure is greater than the solid vapor pressure, below the melting point, the solid vapor pressure is greater than the liquid vapor pressure"

this is a mistake right? because in the gen chem textbooks, it is the other way around.

i was wondering, if there was any other mistakes that other people have seen in the EK books. Is there a thread on this already?

Yes, this is a mistake. When the liquid vapor pressure is greater than the solid vapor pressure, liquid will vaporize but the vapor will condence into a solid. This is, of course, what is know as "freezing." When the liquid vapor pressure is less than the solid vapor pressure, the solid will vaporize but the vapor will condense into a liquid. This is melting.

So you're right and EK is wrong.

Above melting point - solid vapor pressure > liquid vapor pressure
Below melting point- liquid vapor pressure > solid vapor pressure