| Date | November 2014 | Marks available | 1 | Reference code | 14N.1.hl.TZ0.8 |
| Level | HL | Paper | 1 | Time zone | TZ0 |
| Command term | Question number | 8 | Adapted from | N/A |
Question
Cobalt forms the complex \({{\text{[Co(N}}{{\text{H}}_{\text{3}}}{{\text{)}}_{\text{5}}}{\text{Cl]}}^{2 + }}\). Which statements are correct for this complex?
I. The cobalt ion acts as a Lewis acid.
II. The cobalt ion has an oxidation number of +II.
III. There are 90° bond angles between the cobalt ion and the ligands.
A. I and II only
B. I and III only
C. II and III only
D. I, II and III
Markscheme
B
Examiners report
According to IUPAC, oxidation numbers are quoted in Roman numerals, oxidation states in Arabic. The nomenclature is clarified in the new syllabus, taught from September 2014.
