Based on the given compounds, the order of reducing power from the strongest to weakest would be:

Zn > Na2[Zn(OH)4] > ZnCl2 > Zn(OH)2 > H2O > H2SO4 > H2 > HCl > H2S

This means that Zn is the strongest reducing agent in the list, while H2S is the weakest reducing agent.