Following reactions are involved in present reaction
1) Ag+(aq) + Li(s) → Ag(s) + Li+(aq) − 384.4kJ
2) 2Fe(s) + 2Na+(aq) → Fe2+(aq) + 2Na(s) + 392.3kJ
3) 2K(s) + 2H2O(l) → 2KOH(aq) +H2(g) −393.1kJ
In above reaction, reaction 1 and 3 has negative value of δh∘f, while reaction 2 has posiyive value of δh∘f. As per the sign convention positive sign indicates that heat is given out during the reaction, while negative sign indicates heat is to be supplied for reaction to occur. In alternative words, product formed in reaction 2 is stable as compared to reactant. Hence, it is thermodynamically favorable.