To determine which equation describes a reduction process, we need to understand the concepts of oxidation and reduction.
- Oxidation involves the loss of electrons.
- Reduction involves the gain of electrons.
Let's examine each equation closely to identify whether it describes a reduction or oxidation process.
1. Equation 1: \( Mg(s) \longrightarrow Mg^{2+}(aq) + 2e^{-} \)
- Magnesium (Mg) is losing electrons to form \( Mg^{2+} \).
- This is an oxidation reaction because electrons are being lost.
2. Equation 2: \( 2 Cl + 2 e^{-} \longrightarrow 2 Cl^{-} \)
- Chlorine (Cl) is gaining electrons to form \( Cl^{-} \).
- This is a reduction reaction because electrons are being gained.
3. Equation 3: \( Na(s) \longrightarrow Na^{+}(aq) + e^{-} \)
- Sodium (Na) is losing electrons to form \( Na^{+} \).
- This is an oxidation reaction because electrons are being lost.
4. Equation 4: \( Al(s) \longrightarrow Al^{3+}(aq) + 3e^{-} \)
- Aluminum (Al) is losing electrons to form \( Al^{3+} \).
- This is an oxidation reaction because electrons are being lost.
After analyzing all the equations, it is clear that only the second equation involves the gain of electrons, which characterizes a reduction process.
Therefore, the equation that describes a reduction is:
[tex]\[ 2 Cl + 2 e^{-} \longrightarrow 2 Cl^{-} \][/tex]
