Question
Ferroin is a popular redox indicator for one of these reactions. For 10 points each:
[10h] Name these reactions, where periodic changes in the concentrations of components are often accompanied by color changes. Belousov and Zhabotinsky name one of these reactions, while another is named for iodine.
ANSWER: chemical oscillators [or clock reactions; or chemical clocks; accept iodine clock reaction]
[10e] The Belousov-Zhabotinsky reaction relies on the relative concentrations of anions containing this halogen. Uniquely among the halogens, this element with atomic number 35 is a reddish-brown liquid at room temperature.
ANSWER: bromine [or Br]
[10m] The key step in the Belousov–Zhabotinsky reaction relies on bromine being in this oxidation state to act as an oxidizer, as in bromate. Halogens have this oxidation state in oxyanions with three oxygens and an overall -1 (“minus-one”) charge.
ANSWER: +5 [or V; reject “-5”]
<Science - Chemistry>
Summary
| 2023 ACF Fall (Rutgers) | 10/14/2023 | Y | 5 | 10.00 | 60% | 0% | 40% |
Data
| Maryland | Penn | 10 | 10 | 0 | 20 |
| Columbia B | NYU C | 0 | 0 | 0 | 0 |
| Princeton | NYU A | 0 | 0 | 0 | 0 |
| Swarthmore A | Rowan | 0 | 10 | 0 | 10 |
| Columbia A | Swarthmore B | 10 | 10 | 0 | 20 |