question_answer

Standard potentials \[\left( E{}^\circ  \right)\] for some half-reactions are given below:

(I) \[S{{n}^{4+}}+2e\xrightarrow{{}}S{{n}^{2+}};\]\[{{E}^{o}}=+0.15V\]

(II) \[2H{{g}^{2+}}+2e\xrightarrow{{}}Hg_{2}^{2+};\]\[{{E}^{o}}=0.92V\]

(III) \[Pb{{O}_{2}}+4{{H}^{+}}+2e\xrightarrow{{}}P{{b}^{2+}}+2{{H}_{2}}O;\]\[{{E}^{o}}=+1.45V\]

based on the above, which one of the following statements is correct?

A) \[S{{n}^{4+}}\] is a stronger oxidising agent than \[P{{b}^{4+}}\]

B) \[S{{n}^{2+}}\] is a stronger reducing agent than \[H{{g}_{2}}^{2+}\]

C) \[P{{b}^{2+}}\] is a stronger oxidisng agent than \[P{{b}^{4+}}\]

D) \[P{{b}^{2+}}\] is a stronger reducing agent than \[S{{n}^{2+}}\]