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}
• B. $(d S){V, E}>0,(d G){T, p}
• 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)

$(d S){V, E}>0,(d G){T, p}

Answer 2

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) $- ve \Rightarrow < \,0$