Sure, let's identify the synthesis reaction from the given options.
A synthesis reaction is a type of chemical reaction in which two or more simple substances combine to form a more complex substance. This type of reaction is generally represented by the formula:
[tex]\[ A + B \rightarrow AB \][/tex]
Now, let's examine each of the given reactions one by one:
1. [tex]\( 2 H_2 + O_2 \rightarrow 2 H_2O \)[/tex]
- Here, hydrogen ([tex]\( H_2 \)[/tex]) and oxygen ([tex]\( O_2 \)[/tex]) react to form water ([tex]\( H_2O \)[/tex]).
- Two simpler substances (hydrogen and oxygen) combine to form a more complex substance (water).
- This fits the definition of a synthesis reaction.
2. [tex]\( 2 H_2O_2 \rightarrow 2 H_2O + O_2 \)[/tex]
- In this reaction, hydrogen peroxide ([tex]\( H_2O_2 \)[/tex]) decomposes into water ([tex]\( H_2O \)[/tex]) and oxygen ([tex]\( O_2 \)[/tex]).
- This is a decomposition reaction, not a synthesis reaction, because a single compound breaks down into simpler substances.
3. [tex]\( CaCO_3 \rightarrow CaO + CO_2 \)[/tex]
- Calcium carbonate ([tex]\( CaCO_3 \)[/tex]) decomposes into calcium oxide ([tex]\( CaO \)[/tex]) and carbon dioxide ([tex]\( CO_2 \)[/tex]).
- This is another decomposition reaction, where a single compound breaks down into simpler substances.
4. [tex]\( 2 AgNO_3 + Zn \rightarrow 2 Ag + Zn(NO_3)_2 \)[/tex]
- In this reaction, silver nitrate ([tex]\( AgNO_3 \)[/tex]) and zinc ([tex]\( Zn \)[/tex]) react to form silver ([tex]\( Ag \)[/tex]) and zinc nitrate ([tex]\( Zn(NO_3)_2 \)[/tex]).
- This is a single replacement reaction, where zinc replaces silver in the compound.
Based on the definitions and examining each reaction, the first reaction [tex]\( 2 H_2 + O_2 \rightarrow 2 H_2O \)[/tex] is a synthesis reaction.
Thus, the synthesis reaction among the given options is:
[tex]\[ 2 H_2 + O_2 \rightarrow 2 H_2O \][/tex]
So, the correct answer is that the given reaction,
[tex]\[ 2 H_2 + O_2 \rightarrow 2 H_2O \][/tex]
is the synthesis reaction.
