Which reagent is capable under standard conditions, of converting Co2+ (aq) into Co(s) but does not convert Fe2+ (aq) into Fe(s). Which of the following is the best reducing agent under standard conditions, F2(g),Br-(aq),Cu2+(aq),Ni(s),or Li+(aq)? Which of the following is the best oxidizing agent under standard conditions: F2(g),Br-(aq),Cu2+(aq),Ni(s),or Li+(aq)?