I just to know how to identify the substance that is reduced, the substance that is oxidized, the oxidizing agent and the reducing agent in each reaction.
As (s) + ClO3-(aq) → H3AsO3 (aq) + HClO(aq)
CN-(aq) + MnO4-(aq) → CNO-(aq) + MnO2(s)
C2H5OH + MnO4- → C2H3O2 - + MnO2
You look to see which elements change oxidation state. The loss of electrons is oxidation. The gain of electrons is reduction.
Here is a site that will show you how to determine the oxidation state of elements in their compounds.
http://www.chemteam.info/Redox/Redox-Rules.html
Here is some info to get you started.
As changes from zero on the left to +5 on the right.
Cl changes from +5 on the left to +1 on the right.
Tip: Don't change H from +1 or O from -2 unless absolutely necessary.
To identify the substance that is reduced, oxidized, the oxidizing agent, and the reducing agent in a chemical reaction, you can follow these steps:
1. Identify the oxidation states of the elements in the reactants and products of the reaction. You can use the periodic table and the general rules for assigning oxidation states to determine the oxidation states of each element.
2. Compare the oxidation states of the elements in the reactants and products. If an element's oxidation state increases, it is being oxidized. If an element's oxidation state decreases, it is being reduced.
3. The substance being reduced is the one that gains electrons or decreases its oxidation state.
4. The substance being oxidized is the one that loses electrons or increases its oxidation state.
5. The oxidizing agent is the species that causes another element or compound to be oxidized. It itself gets reduced.
6. The reducing agent is the species that causes another element or compound to be reduced. It itself gets oxidized.
Let's apply these steps to the provided reactions:
Reaction 1:
As (s) + ClO3-(aq) → H3AsO3 (aq) + HClO(aq)
- In this reaction, the oxidation state of As changes from 0 in the reactant (As) to +3 in the product (H3AsO3). As the oxidation state of As increases, it is being oxidized.
- The ClO3- ion is also involved in oxidation. Its oxidation state changes from +5 in the reactant to +1 in the product (HClO). It is being reduced.
- Therefore, As is the substance being oxidized and ClO3- is the substance being reduced.
- HClO is acting as the oxidizing agent since it causes As to be oxidized.
- As (s) is acting as the reducing agent since it causes ClO3- to be reduced.
Reaction 2:
CN-(aq) + MnO4-(aq) → CNO-(aq) + MnO2(s)
- In this reaction, the oxidation state of the C atom changes from -1 in the reactant (CN-) to +2 in the product (CNO-). As the oxidation state of C increases, it is being oxidized.
- The oxidation state of Mn changes from +7 in the reactant (MnO4-) to +4 in the product (MnO2). As the oxidation state of Mn decreases, it is being reduced.
- Therefore, C is the substance being oxidized, and Mn is the substance being reduced.
- MnO4- acts as the oxidizing agent since it causes C to be oxidized.
- CN- acts as the reducing agent since it causes MnO4- to be reduced.
Reaction 3:
C2H5OH + MnO4- → C2H3O2- + MnO2
- In this reaction, the oxidation state of the C atom in the alcohol group (C2H5OH) changes from -2 to -1 in the product (C2H3O2-). As the oxidation state of C increases, it is being oxidized.
- The Mn atom changes from +7 in the reactant (MnO4-) to +4 in the product (MnO2). As the oxidation state of Mn decreases, it is being reduced.
- Therefore, the C2H5OH is being oxidized, and MnO4- is being reduced.
- MnO4- acts as the oxidizing agent since it causes C2H5OH to be oxidized.
- C2H5OH acts as the reducing agent since it causes MnO4- to be reduced.
By following these steps, you can identify the substance being oxidized, reduced, oxidizing agent, and reducing agent in a chemical reaction.