Answer :
In order to determine which of the given reactions is a decomposition reaction, let's first recall what a decomposition reaction is. A decomposition reaction is a type of chemical reaction where one compound breaks down into two or more simpler substances.
Let's examine each of the given reactions:
A. [tex]\(2 Mg + O_2 \rightarrow 2 MgO\)[/tex]
This reaction involves magnesium (Mg) reacting with oxygen (O[tex]\(_2\)[/tex]) to form magnesium oxide (MgO). This is a combination reaction, where two reactants combine to form a single product.
B. [tex]\(CaCO_3 \rightarrow CaO + CO_2\)[/tex]
This reaction shows calcium carbonate (CaCO[tex]\(_3\)[/tex]) breaking down into calcium oxide (CaO) and carbon dioxide (CO[tex]\(_2\)[/tex]). Here, a single compound breaks down into two simpler products. This is a decomposition reaction.
C. [tex]\(CH_4 + 2 O_2 \rightarrow CO_2 + 2 H_2O\)[/tex]
This reaction involves methane (CH[tex]\(_4\)[/tex]) reacting with oxygen (O[tex]\(_2\)[/tex]) to form carbon dioxide (CO[tex]\(_2\)[/tex]) and water (H[tex]\(_2\)[/tex]O). This is a combustion reaction, where a hydrocarbon reacts with oxygen to produce carbon dioxide and water.
D. [tex]\(2 H_2O + 2 Na \rightarrow 2 NaOH + H_2\)[/tex]
This reaction involves water (H[tex]\(_2\)[/tex]O) reacting with sodium (Na) to form sodium hydroxide (NaOH) and hydrogen gas (H[tex]\(_2\)[/tex]). This is a single displacement reaction, where sodium displaces hydrogen in water.
Based on the definitions and our analysis, the correct answer is:
B. [tex]\(CaCO_3 \rightarrow CaO + CO_2\)[/tex]
This is the decomposition reaction among the given options.
Let's examine each of the given reactions:
A. [tex]\(2 Mg + O_2 \rightarrow 2 MgO\)[/tex]
This reaction involves magnesium (Mg) reacting with oxygen (O[tex]\(_2\)[/tex]) to form magnesium oxide (MgO). This is a combination reaction, where two reactants combine to form a single product.
B. [tex]\(CaCO_3 \rightarrow CaO + CO_2\)[/tex]
This reaction shows calcium carbonate (CaCO[tex]\(_3\)[/tex]) breaking down into calcium oxide (CaO) and carbon dioxide (CO[tex]\(_2\)[/tex]). Here, a single compound breaks down into two simpler products. This is a decomposition reaction.
C. [tex]\(CH_4 + 2 O_2 \rightarrow CO_2 + 2 H_2O\)[/tex]
This reaction involves methane (CH[tex]\(_4\)[/tex]) reacting with oxygen (O[tex]\(_2\)[/tex]) to form carbon dioxide (CO[tex]\(_2\)[/tex]) and water (H[tex]\(_2\)[/tex]O). This is a combustion reaction, where a hydrocarbon reacts with oxygen to produce carbon dioxide and water.
D. [tex]\(2 H_2O + 2 Na \rightarrow 2 NaOH + H_2\)[/tex]
This reaction involves water (H[tex]\(_2\)[/tex]O) reacting with sodium (Na) to form sodium hydroxide (NaOH) and hydrogen gas (H[tex]\(_2\)[/tex]). This is a single displacement reaction, where sodium displaces hydrogen in water.
Based on the definitions and our analysis, the correct answer is:
B. [tex]\(CaCO_3 \rightarrow CaO + CO_2\)[/tex]
This is the decomposition reaction among the given options.
