Question

A galvanic cell similar to the Daniell cell can be constructed using silver and chromium ions. Based on the following half-reaction potentials, what is the reaction potential for this cell? Cr2+ → Cr3+ + e- Eo = 0.50 V Ag+ + e- → Ag Eo = 0.80 V Cr2+ + Ag+ → Cr3+ + Ag Eo = ______

Answer 1

Solution:

The cell reaction is given as,

Cr2+ + Ag+ $\rightarrow$ Cr3+ + Ag

Half cell reactions are written as,

Oxidation half cell:

Cr2+  $\rightarrow$ Cr3+ + e- , Eo = 0.50 V ---(1)

Reduction half cell:

Ag+ + e-  $\rightarrow$ Ag , Eo = 0.80 V -----(2)

On adding equation 1 and 2, we get,

Cr2+ + Ag+ = Cr3+ + Ag

Eo cell = 0.50 V + 0.80 V = 1.30 V