1. ( a ) What is the emf of a cell made up of a copper electrode and a hydrogen electrode ( PH₂ = 2 atm) in copper sulfate (activity Cu²⁺ = 1) of pH = 1?

( b ) What is the polarity of the cell and which electrode is anode?

2. Calculate whether silver will corrode with hydrogen evolution in deaerated KCN solution, pH = 9, when CN^- activity = 1.0 and Ag(CN)^2- activity is 0.001

3. Zinc is immersed in a solution of CuCl₂ . What is the reaction and at what activity ratio Zn²⁺/Cu²⁺ will the reaction stop?