Given the equation representing a reaction:

[tex]$
Sn^{4+}(aq) + 2e^{-} \rightarrow Sn^{2+}(aq)
$[/tex]

Which term best describes this reaction?

1. ionization
2. neutralization
3. oxidation
4. reduction



Answer :

To determine which term best describes the given reaction:
[tex]\[ Sn^{4+}(aq) + 2 e^{-} \rightarrow Sn^{2+}(aq) \][/tex]

Let's analyze the reaction step-by-step:

1. Identification of species and their charges:
- On the left side of the reaction, we have the ion [tex]\( Sn^{4+} \)[/tex], which has a charge of +4.
- On the right side of the reaction, we have the ion [tex]\( Sn^{2+} \)[/tex], which has a charge of +2.

2. Electron transfer:
- The reaction involves the addition of 2 electrons ([tex]\( 2 e^{-} \)[/tex]) to the [tex]\( Sn^{4+} \)[/tex] ion.
- Electrons are negatively charged particles.

3. Charge changes:
- By gaining 2 electrons, the charge on the [tex]\( Sn \)[/tex] ion changes from +4 to +2.
- This change indicates a decrease in oxidation state from +4 to +2.

4. Defining the type of reaction:
- Oxidation involves the loss of electrons and an increase in oxidation state.
- Reduction involves the gain of electrons and a decrease in oxidation state.
- Ionization usually refers to the process in which atoms or molecules gain or lose electrons to form ions.
- Neutralization refers to a reaction between an acid and a base to form water and a salt.

Since the [tex]\( Sn^{4+} \)[/tex] ion gains 2 electrons, reducing its oxidation state from +4 to +2, this reaction is characterized by a gain of electrons and thus reduction.

Therefore, the correct term to describe this reaction is:

(4) reduction

The answer is 4.