posted by Tara on .
Ethylene glycol (antifreeze) has a specific heat of 2.42 J/(g*K). Calculate q when 3.65 kg of ethylene glycol cools from 240 degrees C to 78 C
q = mass e.g. x specific heat e.g. x (Tfinal-Tinitial) EXCEPT this is just part of it if the ethylene glycol goes through a phase change. Do you have a melting point and boiling point given?
no there is no melting or boliling point given.
I note here (link provided) that the boiling point of ethylene glycol is about 197 C which means that the molecule would be in the vapor state at 240 C (if it didn't decompose). So the person making up this problem failed to take that into account. There would be mass x specific heat vapor x (197-240) and there would be mass x deltaHvap when it condenses at 197. Both of these amounts would be in addition to what I wrote in the first response.