For the reaction:
2H^+(aq)+Zn(s)----->He2(g)+Zn^2+(aq)
a) Write the reduction half-reaction
b) Write the oxidation half-reaction
c) Identify the oxidizing agent
d) Identify the reducing agent
You only need the definitions. Here they are.
1. Oxidation is the loss of electrons.
2. Reduction is the gain of electrons
3. The material oxidized is the reducing agent.
4. The material reduced is the oxidizing
agent.
Zn is 0 on left and +2 on the right.
H is +1 on the left and 0 on the right.
To determine the reduction and oxidation half-reactions, as well as the oxidizing and reducing agents, we need to follow these steps:
Step 1: Assign oxidation numbers to each element in the reaction.
In the given reaction:
2H^+(aq) + Zn(s) → H2(g) + Zn^2+(aq)
Oxidation numbers:
H^+ has an oxidation number of +1.
Zn has an oxidation number of 0 since it is a pure element.
H2 has an oxidation number of 0 since it is a diatomic element.
Zn^2+ has an oxidation number of +2.
Step 2: Identify the elements undergoing a change in oxidation number.
In this reaction, Zn is being oxidized from an oxidation state of 0 to +2, indicating a loss of electrons. H^+ is being reduced from an oxidation state of +1 to 0, indicating a gain of electrons.
a) Reduction half-reaction:
H^+(aq) + e^- → 1/2H2(g)
Explanation:
The reduction half-reaction involves the gain of electrons by H^+(aq) to form H2(g). The coefficient 1/2 is added to balance the hydrogen atoms on both sides of the equation.
b) Oxidation half-reaction:
Zn(s) → Zn^2+(aq) + 2e^-
Explanation:
The oxidation half-reaction involves the loss of electrons by Zn(s) to form Zn^2+(aq). The coefficient 2 is added to balance the electrons on both sides of the equation.
c) Oxidizing agent:
The oxidizing agent is the species that gets reduced. In this case, H^+ is the oxidizing agent since it gains electrons during the reaction.
d) Reducing agent:
The reducing agent is the species that gets oxidized. In this case, Zn is the reducing agent since it loses electrons during the reaction.
Note: It is important to remember that the oxidizing agent and reducing agent are always on opposite sides of the reaction.