Calculate the equilibrium constants for the reactions in problem (22.6).
22.8)
For the reaction given below (at 298 K).
K2Cr O4 (aq) + 2Ag(s) + FeCl 3 (aq) Ag2Cr O4 (s) + 2FeCl 2 (aq) +2 KCl(aq), rGo = - 62.5 kJ. What is the standard cell potential? What is the standard electrode potential for the silver/ silver chromate electrode?
22.9)
Oxidation numbers are associated with atoms in their compounds. These are useful in keeping track of oxidation states of atoms during redox reactions. The oxidation numbers of atoms in their pure states (e.g., Ag(s), O2(g) or Hg (l) are taken to be zero. In H2O, the oxidation number of H is +1 and O is –2. The oxidation number of O is – 2 in its compounds (except in peroxides wherein its oxidation number is –1). The oxidation numbers do not represent the charge on the atom in a molecule. Find the oxidation numbers of N in NO,
N2O, NO2 , N2O4 and N2O5.
22.10)
The Temperature dependence of Eo for the following cell Pt | H 2 | HBr (aq) | AgBr(s) Ag(s) is given (in volts) by Eo = 0.07131 – 4.99 x 10 -4 (T/ K – 298) – 3.95 x 10 -6 [T/ K – 298] 2 where T is in Kelvin. Find rGo,
dE o /dT, rSo and rHo at 298 K.
Ag2Cr O4 (s) + 2FeCl 2 (aq) +2 KCl(aq), 
rGo = - 62.5 kJ. What is the standard cell potential? What is the standard electrode potential for the silver/ silver chromate electrode? 
