7.7 Thermodynamics of reversible cell 7.7.1. Measurement of Electromotive forces(emfs) (2)Weston standard cell Cork sealed with paraffin or wax Saturated Cdso solution CdSO4·-H,O PPT Hg2S0 t Qcd(Hgx Commercial weston standard cell -Cd(5%12%)(Hg) Cdso. oH,O(s)CdSo,(sat Cdso,.H,O(S)HgSO (sHg(+Hg Hg2SO4 4 2 8 CdSO H O 3  Saturated CdSO4 solution Cd(Hg)x + -- Cork sealed with paraffin or wax Commercial Weston Standard cell 4 2 4 4 2 4 8 8 Cd(5% 12%)(Hg) CdSO H O(s) CdSO (sat) CdSO H O(s) HgSO (s) Hg(l)+ 3 3 −         x (2) Weston standard cell 7.7.1. Measurement of Electromotive forces (emf's) §7.7 Thermodynamics of reversible cell