Select the best answer for the question.

17. Which of the following is the balanced chemical equation for the combustion of methane, [tex]CH_4[/tex]?

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

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

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

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



Answer :

To identify the balanced chemical equation for the combustion of methane ([tex]\( \text{CH}_4 \)[/tex]), we need to ensure that the number of each type of atom on the reactants side equals the number on the products side.

The combustion of methane involves methane ([tex]\( \text{CH}_4 \)[/tex]) reacting with oxygen ([tex]\( \text{O}_2 \)[/tex]) to produce carbon dioxide ([tex]\( \text{CO}_2 \)[/tex]) and water ([tex]\( \text{H}_2 \text{O} \)[/tex]).

Let's examine each option:

A. [tex]\( \text{CH}_4 (g) + 2 \text{O}_2 (g) \rightarrow \text{CO}_2 (g) + \text{H}_2 \text{O} (g) \)[/tex]

- Reactants:
- Carbon: 1
- Hydrogen: 4
- Oxygen: 4

- Products:
- Carbon: 1
- Hydrogen: 2
- Oxygen: 3

In this equation, the number of hydrogen and oxygen atoms are not balanced.

B. [tex]\( \text{CH}_4 (g) + 2 \text{O}_2 (g) \rightarrow 2 \text{CO}_2 (g) + 2 \text{H}_2 \text{O} (g) \)[/tex]

- Reactants:
- Carbon: 1
- Hydrogen: 4
- Oxygen: 4

- Products:
- Carbon: 2
- Hydrogen: 4
- Oxygen: 6

In this equation, the number of carbon and oxygen atoms are not balanced.

C. [tex]\( 2 \text{CH}_4 (g) + \text{O}_2 (g) \rightarrow 2 \text{CO}_2 (g) + \text{H}_2 \text{O} (g) \)[/tex]

- Reactants:
- Carbon: 2
- Hydrogen: 8
- Oxygen: 2

- Products:
- Carbon: 2
- Hydrogen: 2
- Oxygen: 3

Again, the number of hydrogen and oxygen atoms are not balanced in this equation.

D. [tex]\( \text{CH}_4 (g) + 2 \text{O}_2 (g) \rightarrow \text{CO}_2 (g) + 2 \text{H}_2 \text{O} (g) \)[/tex]

- Reactants:
- Carbon: 1
- Hydrogen: 4
- Oxygen: 4

- Products:
- Carbon: 1
- Hydrogen: 4
- Oxygen: 4

In this equation, the number of carbon, hydrogen, and oxygen atoms are balanced.

Therefore, the correct balanced chemical equation for the combustion of methane is:

D. [tex]\( \text{CH}_4(g) + 2 \text{O}_2(g) \rightarrow \text{CO}_2(g) + 2 \text{H}_2\text{O}(g) \)[/tex]