# Heat capacity equation units

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1. Mar 31, 2017

### Rizwan Yaseen

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

2. Mar 31, 2017

### BvU

Hello Rizwan,

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 !

3. Apr 1, 2017

4. Apr 1, 2017

### Rizwan Yaseen

Yes units are J/kgmol/Δ K and T in °K and convert them to BTU/kgmol/ΔF and expressT In °F (degree F)

5. May 30, 2017

### maistral

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.

6. Jun 1, 2017

### Staff: Mentor

Are you sure you don't mean lb-moles?

7. Jun 2, 2017

### Rizwan Yaseen

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.

8. Jun 2, 2017

### Staff: Mentor

1 Joule = ? BTU

1 kg = ? lb

1 kg-mole = ? lb-moles

1 degree centigrade = ?? degrees F

Fill in the ??s