To determine which molecule is oxidized in the given redox reaction:
[tex]\[ 6 CO_2 + 6 H_2O \rightarrow C_6H_{12}O_6 + 6 O_2 \][/tex]
we need to identify the changes in oxidation states of the molecules involved in the reaction.
1. Identify the reactants and products:
- Reactants: [tex]\( CO_2 \)[/tex] and [tex]\( H_2O \)[/tex]
- Products: [tex]\( C_6H_{12}O_6 \)[/tex] (glucose) and [tex]\( O_2 \)[/tex]
2. Recognize the general process in photosynthesis:
- In photosynthesis, carbon dioxide ([tex]\( CO_2 \)[/tex]) is reduced to form glucose ([tex]\( C_6H_{12}O_6 \)[/tex]).
- Water ([tex]\( H_2O \)[/tex]) is oxidized to produce oxygen ([tex]\( O_2 \)[/tex]).
3. Determine the oxidation state changes:
- Carbon in [tex]\( CO_2 \)[/tex] changes from [tex]\( +4 \)[/tex] in [tex]\( CO_2 \)[/tex] to various states in glucose, where it is reduced.
- Hydrogen in [tex]\( H_2O \)[/tex] remains +1 and oxygen in [tex]\( H_2O \)[/tex] is -2.
- Oxygen in [tex]\( H_2O \)[/tex] is oxidized to [tex]\( O_2 \)[/tex] where it changes from [tex]\( -2 \)[/tex] in [tex]\( H_2O \)[/tex] to 0 in [tex]\( O_2 \)[/tex].
4. Conclusion:
- Since oxidation involves an increase in oxidation state, the molecule that is oxidized in this redox reaction is [tex]\( H_2O \)[/tex], because the oxygen in [tex]\( H_2O \)[/tex] goes from an oxidation state of -2 to 0 when it becomes [tex]\( O_2 \)[/tex].
Therefore, the molecule that is oxidized in the given redox reaction is [tex]\( H_2O \)[/tex].
