# Calculate Emf of the Following Cell at 25 °C : - Chemistry

Numerical

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+ | H20.00 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
E_(cell)^0 = E^0 H^+ //H_2 -> E^0 Fe^(2+) //Fe

=> E_(cell)^0 = 0 - (-0.44) = 0.44V

The Nernst equation for the cell reaction at 25° C will be

E_(cell) = E_(cell)^0 - (0.0591)/2 log  [Fe^(2+)]/[H^+]^(2+)

= 0.44 - (0.059)/2 log  (0.001)/(0.01)^2

=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

Is there an error in this question or solution?