10. 11. Given the following reactions Determine the oxidation number for the indicated element in each of the following substances: (a) S in SO, (b) C in COCI, (c) Mn in KMnO4, (d) Br in HBrO, (e) P in PF3 12. CaCO3(s) CaO (s) + CO(g) C (s, graphite) + O(g) CO (g) the enthalpy of the reaction is A) 215.4 B) 571.6 C) -215.4 D) -571.6 E) 7.01 104 - kJ. 15. CaCO3 (s) CaO (s) + C (s, graphite) + O (g) 178.1 kJ C) 298.15 K and 1 torr D) 273.15 K and 1 pascal E) 273.15 K and 1 torr AH--393.5 kJ Standard temperature and pressure (STP), in the context of gases, refers to A) 298.15 K and 1 atm B) 273.15 K and 1 atm 13. Give the numerical values of n and I corresponding to each of the following orbital designations: (a) 3p, (b) 2s, (c) 4f, (d) 5d 14. For each element indicate the valence electrons, core electrons and unpaired electrons: (a) carbon, (b) sulfur, (c) silicon, (d) potassium 3