Certainly! Let's analyze the given oxidation-reduction reaction to determine which element has lost electrons.
The reaction is as follows:
[tex]\[
4 \text{Li} + 2 \text{CoO} \rightarrow 2 \text{Co} + \text{Li}_2\text{O}
\][/tex]
In an oxidation-reduction (redox) reaction, one element is oxidized (loses electrons) and another element is reduced (gains electrons).
1. Identify Oxidation States Before the Reaction:
- Lithium (Li): The standard oxidation state of lithium in its elemental form is 0.
- Cobalt in [tex]\(\text{CoO}\)[/tex] (cobalt(II) oxide): Here, cobalt typically has an oxidation state of +2.
- Oxygen in [tex]\(\text{CoO}\)[/tex]: Oxygen usually has an oxidation state of -2 in compounds.
2. Identify Oxidation States After the Reaction:
- Lithium in [tex]\(\text{Li}_2\text{O}\)[/tex]: In lithium oxide, each lithium atom has an oxidation state of +1.
- Cobalt (Co): Here, the cobalt is in its elemental form, which has an oxidation state of 0.
- Oxygen in [tex]\(\text{Li}_2\text{O}\)[/tex]: The oxidation state remains -2 in compounds.
3. Determine the Changes in Oxidation State:
- Lithium (Li):
- Initially: 0
- Finally: +1
- Change: [tex]\( 0 \rightarrow +1 \)[/tex] (Oxidation; loss of electrons)
- Cobalt (Co):
- Initially: +2 (in [tex]\(\text{CoO}\)[/tex])
- Finally: 0
- Change: [tex]\( +2 \rightarrow 0 \)[/tex] (Reduction; gain of electrons)
- Oxygen (O):
- Initially: -2
- Finally: -2
- No change in oxidation state.
4. Observing Electron Transfer:
- Lithium goes from 0 to +1, losing one electron.
- Cobalt goes from +2 to 0, gaining two electrons.
From this analysis, we can see that lithium (Li) loses electrons and thus is oxidized.
Therefore, the element that has lost electrons in this oxidation-reduction reaction is:
C. Li
