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Topic: Specific heat capacity for 50% of ethanol water mixture  (Read 7284 times)

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Offline ferris

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Specific heat capacity for 50% of ethanol water mixture
« on: December 12, 2017, 11:04:58 AM »
Hello, can somebody tell me the specific heat capacity for 50% ethanol water mixture? Need to put in this information in my thesis, please give me a reliable reference link if possible. Thank you so much

Offline Enthalpy

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Offline XeLa.

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Re: Specific heat capacity for 50% of ethanol water mixture
« Reply #2 on: December 13, 2017, 07:50:47 PM »
Out of curiosity, does the heat capacity of a mixture follow any sort of estimable expression, possibly described given the specific heat capacities of the pure compounds, as well as the molar fraction? I tried plotting the data given by Enthalpy, and it appeared to follow a second-order polynomial increase, followed by a rough linear regression. Would the trend more so pertain to the interaction between molecular at the molecular scale?

I was just interested.

Offline Enthalpy

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Re: Specific heat capacity for 50% of ethanol water mixture
« Reply #3 on: December 14, 2017, 08:58:00 AM »
For simple mixtures and estimates 2% accurate, I would just add the heat capacities of the component amounts.

Only because ethanol+water is knowingly abnormal (the water and ethanol volumes don't add), and because ferris expressly asked, did I look for better data.

Note that the table is only a correction to the linear interpolation. And I have no opinion whatsoever about how to estimate such a correction.

Offline XeLa.

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Re: Specific heat capacity for 50% of ethanol water mixture
« Reply #4 on: December 16, 2017, 09:06:02 AM »
Okay, thanks Enthalpy! I guess since the two are miscible in each other, then you wouldn't expect to add 25 mL of one and 50 mL of the other, and achieve a 75 mL solution. That makes sense! I'll have to look at it more in my own time.

Online Borek

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Re: Specific heat capacity for 50% of ethanol water mixture
« Reply #5 on: December 16, 2017, 10:38:01 AM »
Not exactly - 25.0 mL EtOH + 50.0 mL of water yields 72.8mL, 50.0 mL EtOH + 25.0 mL of water yields 72.5 mL. That's assuming anhydrous EtOH.
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