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Chemistry Forums for Students => High School Chemistry Forum => Topic started by: fatkatie on December 29, 2020, 01:22:01 PM

Title: sodium acetate specific heat
Post by: fatkatie on December 29, 2020, 01:22:01 PM

I would like to know the specific heat of melted sodium acetate. 

I just obtained some hand warmers that use the phase change of this material to create heat.  You "recharge" the hand warmer by boiling the warmer in water.  The salt then melts.  Removing it from the heat, it "super cools(?)" and does not begin to recrystallize until you trigger it with a metallic button contained within the package.

I noticed that when a warmer was used right out of the pot (at boiling temperature) the warmer lasted a very long time without the need to trigger the re-crystallization.  What is the specific heat of liquid sodium acetate once it become liquid (somewhere around 135F)?  Is it greater than water?

Thank you.  (1 year of chemistry and physics in school ... a long long time ago when Freska contain cyclamate.)

Title: Re: sodium acetate specific heat
Post by: fatkatie on December 30, 2020, 04:57:29 PM

So it looks like it is higher than water if I read this correctly.

https://www.researchgate.net/publication/324721627_MEASUREMENT_OF_VARIATION_IN_SPECIFIC_HEAT_OF_SODIUM_ACETATE_TRI-HYDRATE
 (https://www.researchgate.net/publication/324721627_MEASUREMENT_OF_VARIATION_IN_SPECIFIC_HEAT_OF_SODIUM_ACETATE_TRI-HYDRATE)
sodium acetate is 4.88 kJ/kg-K

Title: Re: sodium acetate specific heat
Post by: Corribus on January 03, 2021, 02:30:55 PM

Well it can't be pure anydrous sodium acetate, first of all, because the melting point of anhydrous sodium acetate is above the boiling point of water. The hydrated salt melting point is lower, so that's what you should be looking for.