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In a catalytic converter, nitrogen dioxide, NO2, undergoes m…

In a catalytic converter, nitrogen dioxide, NO2, undergoes metal catalyzed reduction to form nitrogen, N2, and oxygen, O2. A balanced equation is provided below. The equation is written with an unconventional coefficient of 1/2 for nitrogen so that the equation is for 1 mole of nitrogen dioxide, so that energies can easily be calculated per mole. NO2(g)   →  1/2 N2(g)  +  O2(g) ΔHr = -33 kJ/mol ΔSr = +61 J/(mol.K) Given the provided enthalpy and entropy of reaction values, determine the Gibbs energy of this reaction at 500°C, the temperature inside a catalytic converter, and decide if the reaction is spontaneous or not at this temperature. Use the equation ΔG = ΔH – TΔS and remember to use the correct units throughout. K = °C + 273

The image above is of an enzyme, superoxide dismutase, abbre…

The image above is of an enzyme, superoxide dismutase, abbreviated as SOD, which performs an important role in controlling potentially toxic oxygen structures in biology. Enzymes are large, complicated structures that can contain thousands of atoms, and so no attempt to show individual atoms is even attempted in most representations of enzymes, as you can see above. SOD reacts with the superoxide anion, -O2, converting it into molecular oxygen, O2. The superoxide anion can be toxic in most biochemical environments, and its concentration needs to be controlled. This is the role of the SOD enzyme. The chemically reactive part of the SOD enzyme is a copper atom, Cu. The copper atom is buried within the SOD structure in the form of a dilation, Cu2+, and we can write another representation of the enzyme as Cu2+-SOD, which focuses on the important copper atom in the enzyme.   A simplified form of the chemical reaction by which SOD converts superoxide, -O2, into oxygen, O2, is shown below: Cu2+−SOD + −O2 → Cu+−SOD + O2  In this reaction, does the Cu2+ undergo oxidation or reduction?