Question

Multiple choice: 3. (5 pts.) The oxidation of copper metal by iron (III) chloride used in the etching of circuit boards goes as follows: 2 Fe3+ (aq) + Cu (s) → 2 Fe2+ (aq) + Cu2+ (aq) The reduction potential for the Fe3+/Fe2+ and Cu2+/Cu pair are +0.772 V and -0.340 V, respectively. The concentrations are [Fe3+] = 1.24 M, [Fe2+] = .248 M, and [Cu2+] = .342 M. The electrical potential for this cell at 25.00C is: (a) +1.057 V (bhmt0.380 V (c) +1.112 V (d) -4.29 V 4. (5 pts.) A pair of elementary reaction occurs as follows: 2 A (aq) +3C The forward and reverse rate constants are 35.32 M-min-1 and 24.41 M-2min-1, respectively. The equilibrium constant for this reaction is: (a) 0.572 M (bilm1.45 M (c) 2.70 M (d) 0.517 M-1 8.mmml5 pts.) Given that the electronegativity values for the elements Cr and S are Xcx = 1.66 and Xs = 2.58, the partial ionic character of the Cr - S bond within the Cr2S3 unit is: (a) 0.191 (blub.895 (c) 0.702 (d) 0.335