The direct conversion of `A` to `B` is difficult hence it is carried out by the following shown path `underset(A)underset(uarr)(C)rarrDunderset(B)underset(darr)`
Given,
`DeltaS_((A rarr C)) = 50 eu`
`DeltaS_((C rarr D)) =30 eu`
`DeltaS_((B rarr D)) = 20 eu`
where eu is the entropy unit, then `DeltaS_((A rarr B))` is

Options

A. `+100` e.u.
B. `+60` e.u.
C. `-100` e.u.
D. `-60` e.u.

Answer

B

Explanation

`Delta S_((A rarr B))=Delta S_((A rarr C))+Delta S_((C rarr D))-Delta S_((B rarr D))`
`= 50+30-20 = 60` e.u.