Answer Happy

Mean atomic weights Ag = 107.9; C = 12.01; Cl = 35.45; H = 1; Fe = 55.85; K= 39.1; Na = 22.9; Ni = 58.69; Mg-24.3, O = 16; S = 32.06; Zn = 65.37. Gas constant R = 8.3143 J mol-¹ K-¹ Faraday's constant = 96485 Coulomb mol-¹. Data 2Al(s) + 1.5 O₂(g) → Al2O3 (s) 0.502 + H₂H₂O(1) Ni(s) + O2 + H₂ →Ni(OH)2(s) Mg(s) + O₂ + H₂ →Mg(OH)2(s) Ba(s) +S(s) +202(g) → BaSO4 (S) AG -1675100+ 313.2T J mol-¹ AG-237141 J mol¹(at 298.15K) AG° -455829 J mol-¹ (at 298.15K) AG-833717 J mol (at 298.15K) AG (25 °C) = -1,370,000 J mol¹ of BaSO4 Submit all diagrams with drawings!! Note that question 4 requires FactSage calculations!! Note - always find solution through 4G rather than AE since some reactions do not have electron transfer and the use of AE or Eº is incorrect. 1 (15%). a) (10%) Calculate the minimum pH required to recover nickel metal from aqueous solution. containing 0.1 m Ni²+ ions using 1 atm hydrogen gas at 25°C. Hint: derive equation linking Niº, Ni²+, H+ and H₂, then solve for pH. diagram and nment if b) (5%) Analyse the Eh-pH diagram, indicate condition from a) on the recovery of Ni is possible, and what are possible limitations. Ni-H2O, 298.15 K m = 0.1 1.3. 1.1 0.9 0.7 0.5 0.3 Ni[+] 0.1 -0.1 -0.3 -0.5 -0.7 -0.9 -1.1 -1.3 E(volts) 0 6 Ni₂H(s) 8 pli 10 12 NiO₂(H₂O)(s) NiQOH(s) NiO(s) Ni(s) 14 16 HNIO₂ 18