To determine which reactions are single displacement reactions, we first need to understand the definition of a single displacement reaction. A single displacement reaction involves one element being replaced by another in a compound, often following the general formula:
[tex]\[ A + BC \rightarrow AC + B \][/tex]
Given the list of reactions, let's analyze each one to see if it fits this pattern:
1. [tex]\(2 \text{NaBr} + \text{CaF}_2 \rightarrow 2 \text{NaF} + \text{CaBr}_2\)[/tex]
This reaction involves the exchange of ions between two compounds without a single element displacing another. Therefore, it is not a single displacement reaction.
2. [tex]\(\text{SnO}_2 + 2 \text{H}_2 \rightarrow \text{Sn} + 2 \text{H}_2 \text{O}\)[/tex]
In this reaction, hydrogen (H) displaces tin (Sn) from its oxide, resulting in tin metal (Sn) and water ([tex]\(\text{H}_2 \text{O}\)[/tex]). This follows the pattern [tex]\(A + BC \rightarrow AC + B\)[/tex], indicating it is a single displacement reaction.
3. [tex]\(4 \text{Na} + \text{O}_2 \rightarrow 2 \text{Na}_2\text{O}\)[/tex]
Sodium (Na) reacts with oxygen (O2) to form sodium oxide ([tex]\(\text{Na}_2 \text{O}\)[/tex]). This is a synthesis reaction rather than a single displacement reaction.
4. [tex]\(2 \text{KClO}_3 \rightarrow 2 \text{KCl} + 3 \text{O}_2\)[/tex]
This reaction represents the breakdown of potassium chlorate ([tex]\(\text{KClO}_3\)[/tex]) into potassium chloride (KCl) and oxygen gas ([tex]\(\text{O}_2\)[/tex]). It is a decomposition reaction rather than a single displacement reaction.
5. [tex]\(2 \text{Al} + 6 \text{HCl} \rightarrow 2 \text{AlCl}_3 + 3 \text{H}_2\)[/tex]
In this reaction, aluminum (Al) displaces hydrogen (H) from hydrochloric acid (HCl), producing aluminum chloride ([tex]\(\text{AlCl}_3\)[/tex]) and hydrogen gas ([tex]\(\text{H}_2\)[/tex]). This fits [tex]\(A + BC \rightarrow AC + B\)[/tex], indicating a single displacement reaction.
Therefore, the single displacement reactions are:
- [tex]\(\text{SnO}_2 + 2 \text{H}_2 \rightarrow \text{Sn} + 2 \text{H}_2 \text{O}\)[/tex]
- [tex]\(2 \text{Al} + 6 \text{HCl} \rightarrow 2 \text{AlCl}_3 + 3 \text{H}_2\)[/tex]
Hence, the correct answers are reactions 2 and 5.
Thus, the reactions that are single displacement reactions are:
[tex]\[ [1, 2, 5] \][/tex]
