Question
A potassium salt of an anion (“AN-i-on”) containing this metal is a test for alcohols, and was used in an old type of breathalyser test. For 10 points each:
[10m] Name this metal, which appears in an anion with seven oxygen atoms that is orange in solution, but turns to green upon reduction by an alcohol.
ANSWER: chromium [accept Cr; prompt on dichromate]
[10h] Another colour change can be seen in the plus-two oxidation state of this metal. This metal forms a pink solution in its hexa⋅aqua(II) ion when dissolved in water, but when concentrated hydrochloric acid is added, the solution turns blue.
ANSWER: cobalt [accept Co]
[10e] Chromium and cobalt are examples of this block of elements on the periodic table, known for forming coloured complexes and having variable oxidation states.
ANSWER: transition metals [accept d-block elements]
Summary
| 2023 UMN COOT | 08/19/2023 | Y | 3 | 16.67 | 100% | 33% | 33% |
Data
| Jeff Weiner Fan Club | Our Job is Buzz | 10 | 10 | 10 | 30 |
| doubleplusnegfive | Palestrina Sawayama | 0 | 0 | 10 | 10 |
| BHSU | Weird Klaus Barbie | 0 | 0 | 10 | 10 |