Problem 1An excavated ancient Chinese bronze carillon was covered by rust containing CuCl, CuX2O and CuX2(OH)X3Cl. Simulation showed CuCl forms first under air and Cl-containing water; CuX2(OH)X3Cl is then produced by routes (a) CuClCuX2OCuX2(OH)X3Cl and (b,c) CuClCuX2(OH)X3Cl directly. Standard Gibbs energies of formation (kJ mol⁻¹, 298 K): CuX2O(s) −146, CuO(s) −130, CuCl(s) −120, CuX2(OH)X3Cl(s) −1338, ClX−(aq) −131, OHX−(aq) −157, HX2O(l) −237. (1.1) (i) Write balanced equations for (a) CuClCuX2O, (b) CuX2OCuX2(OH)X3Cl and (c) CuClCuX2(OH)X3Cl; (ii) calculate ΔrG0(298K) for each; (iii) decide the direction of (a) in air at c(HCl)=1.0×10−4 mol dm⁻³. (1.2) Rate constants of (c): kc=1.29×10−4 mol dm⁻³ s⁻¹ at 25 °C and 2.50×10−4 at 40 °C: (i) find the activation energy; (ii) assign the reaction order; (iii) given that the rate-determining step is monolayer adsorption of OX2 on CuCl, write the rate equation and the condition for the order in (ii). (1.3) A Cu plate is split; part Cu(1) is hammered. For the cell Cu(1)∣CuSOX4(aq)∣Cu(2) with E=ΦR−ΦL, is E<0, =0 or >0? Give the net cell reaction. (1.4) In a Cu–Zn alloy (xCu=0.750) with fcc structure and density 8.51 g cm⁻³, calculate the radius of the statistical atoms. (Ar(Cu)=63.5, Ar(Zn)=65.4.)Solutions: 1