Match the following

Answer

A, B, C, D

Explanation

Half cell reaction A) `Pt//Fe^(+2), Fe^(+3)`
Reversible changes occuring at these electodes involves oxidation (or) reaction `Fe^(+2) iff Fe^(+3) + e^(-) overset("right")to ` oxidation takes place `underset("left")(larr)` reduction takes place
B) `Pt//H_2//H^(+)` standard hydrogen electrode , platinum plate dipped in to solution of protons will one molar concentration at ` 25^(@)C` hydrogen gas passed over Pt plate at one atom ` underset(aq)(2H^(+)) + 2e^(-) to underset((g))(H_2)`
C) `Pt//Hg//Hg_2^(2+)` Metal - metal ion half cell ` 2Hg to Hg_2^(+2) + 2e^(-)`
D) `Pb//PbSO_4//SO_4^(-2)` Metal sparingly soluble salt half cell ` Pb iff Pb^(+2) + 2e^-`
`Pb^(+2) + SO_4^(2-) iff PbSO_(4(s))`