5. The systematic name for Cu2O is (A)copper oxide　(B)copper(I) oxide　(C)copper(II) oxide　(D)copper(III) oxide

6. Given that the enthalpy required to convert CHCl3(g) to gaseous C, H, and Cl atoms is 1397 kJ/mol and that the dissociation enthalpy of a C-H bond is 413 kJ/mol, what is the bond dissociation enthalpy of a C-Cl bond？ (A)328 kJ/mol　(B)603 kJ/mol　(C)984 kJ/mol　(D)1397 kJ/mol