Choose the two half-reactions from a table of standard reduction potentials that most closely approximate the reaction that occur within the battery (Pacemaker). What is the standard voltage generated by a cell operating with these half-reactions? (i got +3.85V). The actual Voltage is about +3.5V)

Question

Choose the two half-reactions from a table of standard reduction potentials that most closely approximate the reaction that occur within the battery (Pacemaker). What is the standard voltage generated by a cell operating with these half-reactions? (i got +3.85V). The actual Voltage is about +3.5V)
2Li(s)+ Ag2CrO4(s)---> Li2CrO4(s)+2Ag(s)
Calculate the voltage at body temperature, 37°C. (How do i determine Q with no concentration or pressure values given)?

DrBob222 · Answer

The problem asks for "standard" voltage. That, to me, means at so-called standard state which for cells is 1M concn and 1 atm pressure. I looked up Li potential and found something like -3.05 as a reduction and Ag as aboaut 0.8 as an oxdn. Your tables may give numbers that have CrO4^2- in them and it would be better to use those.