Question 21 of 142

The standard reduction potential at 290 K for the following half reactions are,

(i) Zn2+ + 2e— → Zn(s);      E° = -0.762 V

(ii) Cr3+ + 3e → Cr(s);          E° = -0.740 V

(iii) 2H+ + 2e → H2(g); ·      E° = -0.000 V

(iv) Fe3+ + e → Fe2+;         E° = +0.77V

Which is the strongest reducing agent?

(a) Zn

(b) Cr

(c) Fe2+

(d) H2