Question

The factor of $\Delta G$ values is important in metallurgy. The $\Delta G$ values for the following reactions at $800^{\circ} C$ are given as $S _{2}(g)+2 O _{2}(g) \longrightarrow 2 SO _{2}(g) ; \Delta G=-544 \,kJ$ $2 Zn (s)+ S _{2}(g) \longrightarrow 2 ZnS (s) ; \Delta G=-293 \,kJ$ $2 Zn (s)+ O _{2}(g) \longrightarrow 2 ZnO (s) ; \Delta G=-480\, kJ$ The $\Delta G$ for the reaction, $2 ZnS (g)+3 O _{2}(g) \longrightarrow 2 ZnO (g)+2 SO _{2}(g)$ will be

• A. -731 kJ
• B. - 787 kJ
• C. -534 kJ
• D. -554 kJ

Answer 1

Answer: (A)

-731 kJ

Answer 2

$=\\{-480+(-544)\\}-(-293)$ $=-480-544+293=-731 \,kJ$