Question

select the correct answer.
methane burns in oxygen to produce carbon dioxide and water. which of the following represents a preliminary, unbalanced equation with the
correct chemical formulas?
a. ch4 + o2 → co2 + h2o
b. ch4 + co2 → o2 + h2o
c. co2 + h2o → ch4 + o2
d. ch4 → o2 + co2 + h2o

Explanation:

Step1: Analyze reactants and products

Reactants are methane (\( \text{CH}_4 \)) and oxygen (\( \text{O}_2 \)). Products are carbon dioxide (\( \text{CO}_2 \)) and water (\( \text{H}_2\text{O} \)).

Step2: Check each option

• Option A: \( \text{CH}_4+\text{O}_2

ightarrow\text{CO}_2+\text{H}_2\text{O} \) has correct reactants and products (unbalanced).

• Option B: \( \text{CH}_4+\text{CO}_2

ightarrow\text{O}_2+\text{H}_2\text{O} \) has wrong reactants (\( \text{CO}_2 \) is a product, not a reactant here).

• Option C: \( \text{CO}_2+\text{H}_2\text{O}

ightarrow\text{CH}_4+\text{O}_2 \) has reactants and products swapped.

• Option D: \( \text{CH}_4

ightarrow\text{O}_2+\text{CO}_2+\text{H}_2\text{O} \) is missing oxygen as a reactant.

So, the correct unbalanced equation with correct chemical formulas is Option A.

Answer:

A. \( \text{CH}_4+\text{O}_2
ightarrow\text{CO}_2+\text{H}_2\text{O} \)