Question

Which of the following is an example of coupled reactions that are likely to be overall spontaneous as written (select all that apply)? A + B -> C + D ΔG° = -10 kJ mol-1 / E + F -> C ΔG° = 2 kJ mol-1 A + B -> C + D ΔG° = 10 kJ mol-1 / D + E -> F ΔG° = -2 kJ mol-1 A + B -> C + D ΔG° = -10 kJ mol-1 / C + E -> F ΔG° = 2 kJ mol-1 A + B -> C + D ΔG° = -10 kJ mol-1 / A + 2 B -> E ΔG° = 2 kJ mol-1

Answer 1

answer : 1 , 3 ,4

1) A + B -> C + D ΔG° = -10 kJ mol-1 / E + F -> C ΔG° = 2 kJ mol-1 -------- spontaneous.

A + B -> C + D ΔG° = -10 kJ mol-1

E + F -> C        ΔG° = 2 kJ mol-1

____________________________

A + B + E + F -----------> 2 C + D , ΔG° = - 8 kJ mol-1

this is spontenous.

3) A + B -> C + D ΔG° = -10 kJ mol-1 / C + E -> F ΔG° = 2 kJ mol-1 ----------- spontaneous

A + B -> C + D ΔG° = -10 kJ mol-1

C + E -> F ΔG° = 2 kJ mol-1

_______________________________

A + B + E   ---------> D + F , ΔG° = - 8 kJ mol-1

this is spontenous.

4) A + B -> C + D ΔG° = -10 kJ mol-1 / A + 2 B -> E ΔG° = 2 kJ mol-1 ----------- spontaneous

A + B -> C + D ΔG° = -10 kJ mol-1

A + 2 B -> E ΔG° = 2 kJ mol-1

----___________________________

2 A + 3 B -------------> C + D + E , ΔG° = -8 kJ mol-1

this is spontanous.