Standard Westen Cell Chemistry Notes
Standard Westen Cell :
Following properties are found in this cell:
- It is a fixed cell which gives re-produced electromotive force.
- It is highly reversible.
- Temperature coefficient of this cell is very low.
→ Electromotive force of this cell at 298 K is 1.0183 V and the value of temperature coefficient is – 0.00005 V K-1 which is very negligible. It is also called cadmium cell. As per fig. 3.17, an apparatus is made of glass with H-shape whose lower ends are fused with platinum wire. Cd-Hg-amalgam is filled in bottom of right tube in which 12.5% part of cadmium is present.
→ Above this, CdSO4. \(\frac{8}{3}\)H2O salt is filled and supersaturated CaSO4 solution is filled in upper remaining part. Hg is filled at lower end towards left side, a paste (calomel) of Hg and HgSO4 is filled above it and then solid CdSO4.\(\frac{8}{3}\) H2O salt is filled and supersaturated CdSO4 solution is filled in remaining part. When cell is working then:
