The free energy change for the following reactions are given below
`C_(2)H_(2)(g)+(5)/(2)O_(2)(g)to2CO_(2)(g)+H_(2)O(l)`, `DeltaG^(@)=-1234 kJ`
`C(s)+O_(2)(g)toCO_(2)(g)`, `DeltaG^(@)=-394 kJ`
`H_(2)(g)+(1)/(2)O_(2)(g)toH_(2)O(l)`, `DeltaG^(@)=-237 kJ`
What is the standard free energy change for the reaction
`H_(2)(g)+2C(s)toC_(2)H_(2)(g)` ?

Options

A. `-209` kJ
B. `- 2259` kJ
C. `+ 2259` kJ
D. 209 kJ

Answer

D

Explanation

At equilibrium `DeltaG=0`.