Consider the chemical equations shown here.

[tex]\[
\begin{array}{l}
CH_4(g) + 2O_2(g) \rightarrow CO_2(g) + 2H_2O(g) \\
2H_2O(g) \rightarrow 2H_2O(l)
\end{array}
\][/tex]

What is the equation for the overall reaction obtained by adding these equations?

A. \(CH_4(g) + 2O_2(g) \rightarrow CO_2(g) + 2H_2O(g)\)

B. \(CH_4(g) + 2O_2(g) \rightarrow CO_2(g) + 2H_2O(l)\)

C. [tex]\(CH_4(g) + 2O_2(g) \rightarrow CO_2(g)\)[/tex]



Answer :

To obtain the equation for the overall reaction by adding the given chemical equations, follow these steps:

1. Write Down the Given Equations:

\(CH_4(g) + 2 O_2(g) \rightarrow CO_2(g) + 2 H_2O(g)\)

\(2 H_2O(g) \rightarrow 2 H_2O(l)\)

2. Identify the Common Terms:

In this case, the term \(2 H_2O(g)\) appears on the product side of the first equation and on the reactant side of the second equation.

3. Combine the Equations:

- The \(2 H_2O(g)\) on both sides will cancel out.
- Sum up the remaining reactants and products.

Adding the equations, we get:

\(CH_4(g) + 2 O_2(g) + 2 H_2O(g) \rightarrow CO_2(g) + 2 H_2O(g) + 2 H_2O(l)\)

4. Cancel Out the Common Terms:

After canceling \(2 H_2O(g)\) from both sides (as they appear on both the reactant and product side), the equation simplifies to:

\(CH_4(g) + 2 O_2(g) \rightarrow CO_2(g) + 2 H_2O(l)\)

5. Write Down the Final Balanced Equation:

The overall reaction obtained by adding these equations is:

[tex]\[ CH_4(g) + 2 O_2(g) \rightarrow CO_2(g) + 2 H_2O(l) \][/tex]

Therefore, the equation for the overall reaction is:

[tex]\[ CH_4(g) + 2 O_2(g) \rightarrow CO_2(g) + 2 H_2O(l) \][/tex]