-- Consider a concentration cell. Two Ag-electrodes are immersedin AgNO3 solutions of different concentrations. When the twocompartments have an AgNO3-concentration of 1 M and 0.1 M,respectively, the measured voltage is 0.065 V (note: T in notnecessarily = 25°C ).
The electrochemical behavior of silver nanoclusters (Agn, with nthe number of Ag atoms in the cluster) is investigated using thefollowing electrochemical cells at 298 K:
I. Ag(s) | AgCl (saturated) || Ag+(aq, 0.01M)| Ag(s), E=0.170
II. (Pt electrode) Agn (s, nanocluster) | Ag+(aq,0.01M) || AgCl (saturated) | Ag(s), with E = +1.030 V forAg5 nanocluster and E = +0.430 V for Ag10 nanocluster
The standard reduction potential for Ag+ + e- → Ag, is E0 =+0.800 V.
The two nanoclusters Ag5 and Ag10-nanoclusters have standardpotentials different from the potential of metallic bulksilver.
c. Calculate the standardpotentials of Ag5 and of Ag10 nanoclusters. [for this part useKsp(AgCl)=1.800·10-5;]
d. What happens, if you put theAg10 nanoclusters and – in a second experiment – the Ag5nanoclusters into an aqueous solution of pH=5? Estimate theconsequences using the reduction potentials youcalculated.
