The expression, $$\Delta {\text{G}} = {\text{nRT}}.l{\text{n}}\frac{{{{\text{P}}_2}}}{{{{\text{P}}_1}}},$$ gives the free energy change
A. With pressure changes at constant temperature
B. Under reversible isothermal volume change
C. During heating of an ideal gas
D. During cooling of an ideal gas
Answer: Option A
Solution(By Examveda Team)
We know, the property relation:$$dG = vdp - sdT$$
Which is valid for both reversible and irreversible process since it is a property relation. when the system undergoes isothermal change $$dT = 0$$
$$\eqalign{ & {\text{So, }}dG = vd \cr & \Rightarrow dG = \frac{{nRT}}{P}dP\left( {{\text{for, ideal gas}}} \right) \cr} $$
On, integration
$$ \Rightarrow \Delta G = nRT.ln\frac{{{P_2}}}{{{P_1}}}$$
So, for a system containing ideal gas and undergoing isothermal change of volume or pressure this expression is valid.
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Comments ( 1 )
Related Questions on Chemical Engineering Thermodynamics
A. Maxwell's equation
B. Thermodynamic equation of state
C. Equation of state
D. Redlich-Kwong equation of state
Henry's law is closely obeyed by a gas, when its __________ is extremely high.
A. Pressure
B. Solubility
C. Temperature
D. None of these
A. Enthalpy
B. Volume
C. Both A & B
D. Neither A nor B
Very nice explanation