Electrochemistry

Consider the following reduction processes : Zn²⁺ + 2e^– $$\to$$ Zn(s) ; E^o = – 0.76 V Ca²⁺ + 2e^– $$\to$$ Ca(s); E^o = –2.87 V Mg²⁺ + 2e^– $$\to$$ Mg(s) ; E^o = – 2.36 V Ni² + 2e^– $$\to$$ Ni(s) ; E^o = – 0.25 The reducing power of the metals increases in the order :