Specific heat of a substance at its boiling pt

[jgalt42]

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Hey Guys,

Is there anything special about specific heats of substances at its boiling pt? On a question EK said water's specific heat was infinite because there was no temperature change because water turns into steam.

 

[Compass]

Hey Guys,

Is there anything special about specific heats of substances at its boiling pt? On a question EK said water's specific heat was infinite because there was no temperature change because water turns into steam.

Ehhh... sorta.

The thing about boiling is kind of unique. At boiling point, the water will REMAIN at 100* regardless of how much energy is applied, because you can't heat water to 101* unless you change the pressure. It's a rare exception, and I doubt the MCAT would pull something THIS dastardly.

 

[jgalt42]

Thanks,

Are specific heats of substances constant throughout all its phases or is it unique for each one?

 

[thebillsfan]

diff spec heat for diff phase. will be given to you

 

[Schemp]

yeah, to just add to what compass said. since the temperature doesn't increase when you put in more energy (it goes toward breaking hydrogen bonds instead), the specific heat is technically infinite. but then you have heat of fusion and vaporization and such, so those become relevant at the melting and boiling points.

 

[stockraider]

ok correct me if i'm wrong here, but from what i understand, during a PHASE CHANGE the specific heat will be infinite, that is the q=mc(delta T) equation does not apply, only the q=n(heat of fusion/vaporization) applies. so during phase change c (spec heat) is infinite while the heat of fusion and heat of vaporization have a defined value???