David
28 posts
TimePosted 15/12/2014 11:24:14
David says

Specific Heat

Hello;

As we know that the specific heat (Cp) of dry limestone which is the amount of heat required to increase 1 gram of limestone 1 degree = 0.908 j/g.K.  My quasition is how to calculate the specific heat of limestone with 8.0% moisture?

 

Regards

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Silastman
80 posts
TimePosted 16/12/2014 07:54:52
Silastman says

re Specific Heat

It's question from scool program. Your must calculate heat of heating water in limestone from temperature 298 K up to 373 K & after that heat of evaporation of water and sum it. C1=4.183 J/g K, C2=2259 j/g K.

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David
28 posts
TimePosted 16/12/2014 21:07:15
David says

re Specific Heat

Thank you for your answer but kindly; read the question again and try to understand it. Best regards

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Ted Krapkat
536 posts
TimePosted 17/12/2014 02:54:58

re Specific Heat

Hello David,

Silastman is essentially correct. 

What he is saying is that the specific heat of liquid water is 4.183 J/g.K.  But, above 100C (373K) you will also have to use the latent heat of vaporisation of water (2259 J/g.K).

If there is no evaporation of water in your moist limestone system, the specific heat of the system can be calculated by multiplying the percentage of each component by its Cp and summing the results to give the Cp of the moist limestone ie.

 92/100 *.908 + 8/100*4.183 = 1.17 J/g.K

If there is significant evaporation in your system, then you will have to account for the latent heat of vaporisation of the evaporated portion of the moisture, in a similar manner to the calculation above..

 

Regards,

Ted.

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