Choose the chemical equation that is correctly balanced.
A. [tex]2 Ca ( s )+ Cl _2(g) \rightarrow CaCl _2(s)[/tex]
B. [tex]4 Mg ( s )+ O _2(g) \rightarrow 2 MgO ( s )[/tex]
C. [tex]Li ( s )+ Cl _2(g) \rightarrow 2 LiCl ( s )[/tex]
D. [tex]C ( s )+ O _2(g) \rightarrow CO _2(g)[/tex]
Answer (2)
Check each equation to ensure the number of atoms of each element is the same on both sides.
The first equation, 2 C a ( s ) + C l 2 ( g ) i g h t ha r p oo n u pC a C l 2 ( s ) , is not balanced.
The second equation, 4 M g ( s ) + O 2 ( g ) i g h t ha r p oo n u p 2 M g O ( s ) , is not balanced.
The third equation, L i ( s ) + C l 2 ( g ) i g h t ha r p oo n u p 2 L i Cl ( s ) , is not balanced.
The fourth equation, C ( s ) + O 2 ( g ) i g h t ha r p oo n u pC O 2 ( g ) , is balanced, so the final answer is C ( s ) + O 2 ( g ) i g h t ha r p oo n u pC O 2 ( g ) .
Explanation
Understanding Balanced Equations We need to identify the correctly balanced chemical equation from the given options. A balanced equation has the same number of atoms for each element on both the reactant and product sides.
Analyzing Each Equation Let's analyze each equation:
2 C a ( s ) + C l 2 ( g ) i g h t ha r p oo n u pC a C l 2 ( s ) :
Reactant side: 2 Ca atoms, 2 Cl atoms
Product side: 1 Ca atom, 2 Cl atoms
This equation is not balanced because the number of Ca atoms is not the same on both sides.
4 M g ( s ) + O 2 ( g ) i g h t ha r p oo n u p 2 M g O ( s ) :
Reactant side: 4 Mg atoms, 2 O atoms
Product side: 2 Mg atoms, 2 O atoms
This equation is not balanced because the number of Mg atoms is not the same on both sides.
L i ( s ) + C l 2 ( g ) i g h t ha r p oo n u p 2 L i Cl ( s ) :
Reactant side: 1 Li atom, 2 Cl atoms
Product side: 2 Li atoms, 2 Cl atoms
This equation is not balanced because the number of Li atoms is not the same on both sides.
C ( s ) + O 2 ( g ) i g h t ha r p oo n u pC O 2 ( g ) :
Reactant side: 1 C atom, 2 O atoms
Product side: 1 C atom, 2 O atoms
This equation is balanced because the number of C and O atoms is the same on both sides.
Conclusion Therefore, the correctly balanced chemical equation is C ( s ) + O 2 ( g ) i g h t ha r p oo n u pC O 2 ( g ) .
Examples
Balancing chemical equations is essential in various real-life applications, such as calculating the amount of reactants needed for a chemical reaction or determining the products formed. For example, in the combustion of methane ( C H 4 ) with oxygen ( O 2 ), balancing the equation C H 4 + 2 O 2 i g h t ha r p oo n u pC O 2 + 2 H 2 O allows us to determine that one molecule of methane requires two molecules of oxygen to produce one molecule of carbon dioxide and two molecules of water. This knowledge is crucial in industrial processes, environmental management, and even cooking.
After analyzing each of the equations, the correctly balanced chemical equation is D: C (s) + O₂ (g) → CO₂ (g). This equation maintains equal numbers of each type of atom on both sides of the reaction. Therefore, it exemplifies the law of conservation of mass.
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