To determine the best description of what is happening in the reaction [tex]\(2 C_8H_{18} + 25 O_2 \rightarrow 16 CO_2 + 18 H_2O\)[/tex], let's analyze the changes in oxidation states and identify whether it is a redox reaction.
1. Oxidation States of Carbon:
- In octane ([tex]\(C_8H_{18}\)[/tex]), each carbon atom has an intermediate oxidation state.
- In carbon dioxide ([tex]\(CO_2\)[/tex]), carbon is fully oxidized to an oxidation state of +4.
2. Oxidation States of Oxygen:
- In [tex]\(O_2\)[/tex], oxygen is in its elemental form with an oxidation state of 0.
- In water ([tex]\(H_2O\)[/tex]), oxygen is in an oxidation state of -2.
We observe the following:
- Carbon in C_8H_{18}: Undergoes oxidation as it changes from a reduced state (in the hydrocarbon) to an oxidized state (+4 in [tex]\(CO_2\)[/tex]).
- Oxygen in O_2: Undergoes reduction as it changes from an oxidation state of 0 to -2 in [tex]\(H_2O\)[/tex].
This oxidation-reduction process indicates that electrons are being transferred. Specifically:
- Octane ([tex]\(C_8H_{18}\)[/tex]) acts as the reducing agent because it loses electrons (is oxidized).
- Oxygen ([tex]\(O_2\)[/tex]) acts as the oxidizing agent because it gains electrons (is reduced).
Since there is a change in oxidation states for both carbon and oxygen, and electron transfer takes place, this qualifies the reaction as a redox reaction.
Hence, the answer that best describes what is happening in the reaction is:
- This is a redox reaction in which octane ([tex]\(C_8H_{18}\)[/tex]) is the reducing agent.
