Which of the two reactions in Blue Printing is an oxidation-reduction reaction? What is the oxidizing agent and the reducing agent?
Fe^3+ + C204^-2 (oxalate) -> Fe^2+ + CO3
Fe^2+ + Fe (CN)6^-2 -> Fe3[Fe(CN)6]2
Can the second reaction occur in the absence of light? Explain please!
In 1, Fe^+3 changes from +3 to +2 and each C changes from +3 to +4. The second reaction is not a redox rxn.
Oxidation is the loss of electrons.
Reduction is the gain of electrons.
Which one is the oxidizing agent and the reduction agent?
Can the second reaction occur in the absence of light? Thank you!
To determine which of the two reactions is an oxidation-reduction (redox) reaction, we need to identify the changes in oxidation states of the elements involved. In a redox reaction, there is a transfer of electrons between species, resulting in changes in their oxidation states.
Let's analyze the oxidation states for each reaction:
1. Fe^3+ + C204^-2 (oxalate) -> Fe^2+ + CO3
In this reaction, iron (Fe) goes from a +3 oxidation state (Fe^3+) to a +2 oxidation state (Fe^2+). This represents a reduction, as the oxidation state of Fe decreases. Oxalate (C204^-2) goes from a -2 oxidation state to a +4 oxidation state (-2 to +4), indicating an oxidation. Therefore, this reaction involves redox chemistry.
2. Fe^2+ + Fe (CN)6^-2 -> Fe3[Fe(CN)6]^2
In this reaction, iron (Fe) goes from a +2 oxidation state (Fe^2+) to a +3 oxidation state (Fe^3+). This represents an oxidation, as the oxidation state of Fe increases. Iron in the complex, Fe(CN)6^-2, goes from a +3 oxidation state to a +2 oxidation state, indicating a reduction. Thus, this reaction also involves redox chemistry.
Now, let's determine the oxidizing agent and reducing agent for each reaction:
1. Fe^3+ + C204^-2 (oxalate) -> Fe^2+ + CO3
Iron (Fe^3+) is being reduced to Fe^2+, so it is the oxidizing agent. Oxalate (C204^-2) is being oxidized to CO3, so it is the reducing agent.
2. Fe^2+ + Fe (CN)6^-2 -> Fe3[Fe(CN)6]^2
Iron (Fe^2+) is being oxidized to Fe^3+, so it is the reducing agent. The complex Fe(CN)6^-2 is being reduced to Fe3[Fe(CN)6]^2, so it is the oxidizing agent.
Regarding the second reaction occurring in the absence of light, the reaction is called the "Prussian blue reaction." It is a reaction that is typically catalyzed by light, specifically UV light. In the absence of light, the reaction will proceed at a much slower rate or may not occur at all. The presence of light helps initiate the reaction by providing the necessary energy for the redox process to happen. Therefore, the second reaction requires the presence of light to occur efficiently.