Question
Calculate emf of the following cell at 25 °C:
Fe | Fe2+(0.001 M) || H+ (0.01 M) | H2 (g) (1 bar) | Pt(s)
E°(Fe2+ | Fe) = –0.44 V E°(H+ | H2 ) = 0.00 V
Solution
For the given cell representation, the cell reaction will be Fe(s) + 2H+(aq) → Fe2+(aq) + H2(g)
The standard emf of the cell will be
=0.44-0.02955(log10)
=0.44-0.02955(1)
=0.41045V 0.41V
The Nernst equation for the cell reaction at 25 º C will be
=0.44-0.02955(log10)
=0.44-0.02955(1)
=0.41045V 0.41V