- #1
Pandris
- 3
- 0
Hi here!
(before scriptum. Sorry for my lousy English and LaTex.)
I am a bit confused about entropy change statements:
In most textbooks is given:
\Delta S = n (C_V ln \frac{ \ T_{2}}{T_1} + R ln \frac{ \ V_{2}}{V_1})
where n - moles of gas. And dimension of entropy is [J/K]
But now I have one book there entropy change is defined using specific heats:
<br /> \Delta S = m (c_v ln \frac{ \ p_{2}}{p_{1}} + c_p ln \frac{ \ V_{2}}{V_{1}})<br />
where m - mass of gass, and dimension is [J/(kmol*K)]
I can't understand where this isobaric specific heat gets here!
Ok, I understand that these entropies essentially are given for different measures of amount of gass. First is given for moles, but second for kilograms. (am I right??)
But how to involve specific heats there is obscure for me.
Thanks!
(before scriptum. Sorry for my lousy English and LaTex.)
I am a bit confused about entropy change statements:
In most textbooks is given:
\Delta S = n (C_V ln \frac{ \ T_{2}}{T_1} + R ln \frac{ \ V_{2}}{V_1})
where n - moles of gas. And dimension of entropy is [J/K]
But now I have one book there entropy change is defined using specific heats:
<br /> \Delta S = m (c_v ln \frac{ \ p_{2}}{p_{1}} + c_p ln \frac{ \ V_{2}}{V_{1}})<br />
where m - mass of gass, and dimension is [J/(kmol*K)]
I can't understand where this isobaric specific heat gets here!
Ok, I understand that these entropies essentially are given for different measures of amount of gass. First is given for moles, but second for kilograms. (am I right??)
But how to involve specific heats there is obscure for me.
Thanks!
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