Question

In an irreversible process taking place at constant $T$ and $P$ and in which only pressure-volume work is being done, the change in Gibbs free energy (dG) and change in entropy (dS), satisfy the criteria:

• A. $(d S)_{V, E}<0,(d G)_{T, P}<\, 0$
• B. $(d S)_{V, E}>0,(d G)_{T, p}<\, 0$
• C. $(d S)_{V, E}=0,(d G)_{T, p} = 0$
• D. $(d S)_{V, E}=0,(d G)_{T, p} >\,0$

Answer 1

Answer: (B)

An irreversible process

$\Rightarrow $ spontaneous process

$\Rightarrow (d S)_{v E}$ (change in entropy) $=+ ve >\,0$

$\Rightarrow (d G)_{T, p}$ (change in Gibbs free energy)

$ - ve \Rightarrow < \,0$