Chemistry

Problem

Which mathematical expression defines the standard entropy change,

\Delta S^\circ_{\text{rxn}}

, for a chemical reaction written as

a\,A + b\,B \rightarrow c\,C + d\,D

? a)

\displaystyle \frac{c\,S^\circ_{C} + d\,S^\circ_{D}}{a\,S^\circ_{A} + b\,S^\circ_{B}}

c\,S^\circ_{C} + d\,S^\circ_{D} + a\,S^\circ_{A} + b\,S^\circ_{B}

c\,S^\circ_{C} + d\,S^\circ_{D} - \left(a\,S^\circ_{A} + b\,S^\circ_{B}\right)

a\,S^\circ_{A} + b\,S^\circ_{B} - \left(c\,S^\circ_{C} + d\,S^\circ_{D}\right)