Question

Which reactions are spontaneous?

i. C2H5OH(l) + 3O2(g) Right arrow. 2CO2(g) + 3H2O(l), Delta.G = –36.7 kJ
ii. 2C6H6(l) + 15O2(g) Right arrow. 12CO2(g) + 6H2O(l), Delta.G = –6,405 kJ
iii. CaCO3(s) Right arrow. CaO(s) + CO2(g), Delta.G = 13.0 kJ
iv. Ni(s) + Cl2(g) Right arrow. NiCl2(s), Delta.G = 1,130.28 kJ
i and ii
iii and iv
i and iii
ii and iv

Answer 1

Reactions with ΔG < 0 are spontaneous. Here i (−36.7 kJ) and ii (−6,405 kJ) are spontaneous. So: i and ii.