Question
When this reaction is incomplete, it can leave behind toxic intermediates like acetaldehyde and carbon monoxide. For 10 points each:
[10e] Name this highly exothermic redox reaction that can occur between methane and oxygen.
ANSWER: combustion [accept incomplete combustion or complete combustion]
[10h] Combustion has a high activation energy because oxygen must first undergo a forbidden transition from one of these two states to the other. Atoms in these two states have a total spin of 1 and 0, respectively.
ANSWER: triplet AND singlet [accept in either order]
[10m] At very high temperatures, this element can react with oxygen during combustion, creating pollutants symbolized "[this element]-O-x." A common rocket fuel has two atoms of this element and four atoms of hydrogen.
ANSWER: nitrogen [or N] (The rocket fuel is hydrazine.)
<Science - Chemistry>
Data
Summary
| Tournament | Edition | Exact Match? | Heard | PPB | Easy % | Medium % | Hard % |
|---|---|---|---|---|---|---|---|
| 2025 PACE NSC | 06/07/2025 | Y | 36 | 16.39 | 86% | 69% | 8% |