20. Electrochemistry

Given the following standard reduction potentials,

Hg₂²⁺(aq)  +  2 e^–    2 Hg (l)                                                          E° = +0.789 V

Hg₂Cl₂(s)  +  2 e^–    2 Hg (l)  +  2 Cl^-(aq)                                        E° = +0.271 V

determine K_sp for Hg₂Cl₂(s) at 25 °C.

Ni (s)│Ni²⁺ (aq) ║Cu²⁺ (aq)│Cu (s) cell.

For the redox reaction label: the anode, cathode, half-reactions occurring at each half-cell, direction of electron flow, and direction of neutral ions flow.

$Ni\(\left\)(s\(\right\))+Zn^{2+}\(\left\)(aq\(\right\))\(\rightarrow\) Ni^{2+}\(\left\)(aq\(\right\))+Zn\(\left\)(s\(\right\))$

The diagram that follows represents a molecular view of a process occurring at an electrode in a voltaic cell.

(b) Is the electrode the anode or cathode?

The diagram that follows represents a molecular view of a process occurring at an electrode in a voltaic cell.

(a) Does the process represent oxidation or reduction?

Assume that you want to construct a voltaic cell that uses the following half-reactions: A2+1aq2 + 2 e- ¡ A1s2 Ered ° = -0.10 V B2+1aq2 + 2 e- ¡ B1s2 E°red = -1.10 V You begin with the incomplete cell pictured here in which the electrodes are immersed in water.

(a) What additions must you make to the cell for it to generate a standard emf?