Which of the following is an oxidation reaction?
A.
AuCl4- → AuCl 2- ****
B.
Mn7+ → Mn2+
C.
Cl2 → ClO3-
D.
Co3+ → Co2+
c. Cl in Cl2 lost electrons to to a positive state (Cl+5)
Darn that was my first answer, I just second guessed myself...thank you!
Option A, AuCl4- → AuCl2-, is an example of an oxidation reaction. In this reaction, the oxidation state of gold (Au) changes from +3 to +1, indicating the loss of electrons and an increase in oxidation state.
To determine which of the given reactions is an oxidation reaction, we first need to understand the concept of oxidation and reduction. In an oxidation-reduction (redox) reaction, electrons are transferred between reactants. Oxidation involves the loss of electrons, while reduction involves the gain of electrons.
Let's analyze each given reaction:
A. AuCl4- → AuCl2-:
In this reaction, the Au atom goes from a formal oxidation state of +3 in AuCl4- to +1 in AuCl2-. This means that the Au atom gains two electrons, which indicates reduction, not oxidation.
B. Mn7+ → Mn2+:
In this reaction, the Mn atom goes from a formal oxidation state of +7 in Mn7+ to +2 in Mn2+. This means that the Mn atom gains five electrons, which indicates reduction, not oxidation.
C. Cl2 → ClO3-:
In this reaction, the Cl2 molecule is transformed into the ClO3- ion. The Cl atom in Cl2 goes from an oxidation state of 0 to +5 in ClO3-. This indicates that the Cl atom loses electrons, which suggests oxidation.
D. Co3+ → Co2+:
In this reaction, the Co atom goes from a formal oxidation state of +3 in Co3+ to +2 in Co2+. This means that the Co atom gains one electron, which indicates reduction, not oxidation.
Based on this analysis, the correct answer is C. Cl2 → ClO3-, which is an oxidation reaction because the Cl atom loses electrons, indicating an increase in oxidation state.