19. Solving a chemistry problem

97. During polarography of a copper salt solution against the background of an ammonia buffer solution using a mercury drop electrode, the following data were obtained: at E \u003d - 0.40 V, the wave height on the polarogram h \u003d 2.5 mm; at E = –0.50 V, h = 73 mm, at E = –0.65 V and its subsequent values h = 146 mm. Calculate, using the polarographic wave equation, the half-wave potential and the number of electrons involved in the process.