For the reaction, 2Ag+2H+────▸H2+2Ag+ Standard free energy change (ΔG°)=−nFE° where, n= number of electrons change. F= charge over one mole of electrons i.e. 96500C. E°= standard electrode potential ∵ In the reaction, Ag───▸Ag+ i.e. oxidation of silver takes place and n=2 ∴ΔG°=−2×96500×[(−)0.8] =154400J∕mol=154.4kJ∕mol ∴ Hence, (b) is the correct option.