How to Convert Heat Capacity Equation Units to British Engineering System?

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Discussion Overview

The discussion revolves around converting the heat capacity equation from SI units to the British engineering system. Participants explore the necessary unit conversions and express uncertainty regarding specific conversions and terminology.

Discussion Character

  • Technical explanation
  • Mathematical reasoning
  • Debate/contested

Main Points Raised

  • One participant presents a heat capacity equation but does not specify the units, prompting questions about the context and units involved.
  • Another participant suggests that the equation likely pertains to ice at 0°C and is expressed in J per kmol per Kelvin, proposing a method to convert Joules to BTUs and temperature from Kelvin to Fahrenheit.
  • There is a suggestion to convert units using dimensional analysis, with a note that constants may need to be adjusted afterward.
  • Some participants clarify that the units are J/kgmol/ΔK and express the need to convert these to BTU/kgmol/ΔF, with a question about whether lb-moles should be used instead of kg-moles.
  • One participant expresses confusion about the conversion process and seeks further clarification on specific unit conversions, such as Joules to BTUs and kg to lb.

Areas of Agreement / Disagreement

Participants generally agree on the need for unit conversion but express differing views on the specifics of the conversions and the terminology used, indicating that the discussion remains unresolved.

Contextual Notes

There are uncertainties regarding the exact units and conversion factors, as well as the definitions of terms like kg-mole versus lb-mole, which may affect the conversion process.

Rizwan Yaseen
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How we change the units of Heat capacity equation to British engineering system
Cp=2. 657*10^4 +42. 37T - 1. 425*10^-2T^2
 
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Hello Rizwan, :welcome:

You don't mention any units in your expression. Can I guess it's for ice at 0 C and expressed in J per kmol per Kelvin ?

I don't think the British units system managed to mess up the kmol too, so all you have to do is convert Joules to British dingdongs, so e.g.
if 1 Joule is 0.000947817 BTU,
and 1 K is 9/5 F (+ some constant) multiply by 0.000947817 and divide by 9/5. That's all.

But if you want to mangle it further, you still have to divide by the molar weight to get ##\approx## 0.5 BTU/lbm/F

PS why do I have to google that for you? You can find such conversions all over the place !
 
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BvU said:
Hello Rizwan, :welcome:

You don't mention any units in your expression. Can I guess it's for ice at 0 C and expressed in J per kmol per Kelvin ?

I don't think the British units system managed to mess up the kmol too, so all you have to do is convert Joules to British dingdongs, so e.g.
if 1 Joule is 0.000947817 BTU,
and 1 K is 9/5 F (+ some constant) multiply by 0.000947817 and divide by 9/5. That's all.

But if you want to mangle it further, you still have to divide by the molar weight to get ##\approx## 0.5 BTU/lbm/F

PS why do I have to google that for you? You can find such conversions all over the place !
 
Yes units are J/kgmol/Δ K and T in °K and convert them to BTU/kgmol/ΔF and expressT In °F (degree F)
 
I know this might probably be too late, but you can always use dimensional analysis. Then constants would then begin to appear and you can distribute them afterwards.
 
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Rizwan Yaseen said:
Yes units are J/kgmol/Δ K and T in °K and convert them to BTU/kgmol/ΔF and expressT In °F (degree F)
Are you sure you don't mean lb-moles?
 
Oops sorry sir but it's lb moles I write in a hurry but still this conversion confuse Me How I might get this one.
 
1 Joule = ? BTU

1 kg = ? lb

1 kg-mole = ? lb-moles

1 degree centigrade = ?? degrees F

Fill in the ??s
 

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