Question

analyze a chemical reaction

1. the equation that represents

the chemical reaction shown
is $\ce{ch_{4} + 2o_{2} \
ightarrow co_{2} + 2h_{2}o}$.
which molecules are the
reactants? which molecules
are the products?

1. what do the equation and the model tell you about the number of atoms of each

kind in the reactants and products?

Explanation:

Question 6

Step 1: Identify Reactants

In a chemical equation, reactants are on the left side of the arrow. The equation is \( \text{CH}_4 + 2\text{O}_2
ightarrow \text{CO}_2 + 2\text{H}_2\text{O} \). So reactants are \( \text{CH}_4 \) (methane) and \( \text{O}_2 \) (oxygen, with 2 molecules as indicated by the coefficient 2).

Step 2: Identify Products

Products are on the right side of the arrow. From the equation, products are \( \text{CO}_2 \) (carbon dioxide) and \( \text{H}_2\text{O} \) (water, with 2 molecules as indicated by the coefficient 2).

The chemical equation \( \text{CH}_4 + 2\text{O}_2
ightarrow \text{CO}_2 + 2\text{H}_2\text{O} \) and its molecular model show the law of conservation of mass (atoms are conserved). For each element:

• Carbon (C): 1 atom in \( \text{CH}_4 \) (reactant) and 1 atom in \( \text{CO}_2 \) (product).
• Hydrogen (H): 4 atoms in \( \text{CH}_4 \) (reactant) and \( 2 \times 2 = 4 \) atoms in \( 2\text{H}_2\text{O} \) (product).
• Oxygen (O): \( 2 \times 2 = 4 \) atoms in \( 2\text{O}_2 \) (reactant) and \( 2 + (2 \times 1) = 4 \) atoms (2 in \( \text{CO}_2 \), 2 in \( 2\text{H}_2\text{O} \)) in products.

The model visually represents molecules: 1 \( \text{CH}_4 \) (1 C, 4 H), 2 \( \text{O}_2 \) (each \( \text{O}_2 \) has 2 O), 1 \( \text{CO}_2 \) (1 C, 2 O), and 2 \( \text{H}_2\text{O} \) (each \( \text{H}_2\text{O} \) has 2 H, 1 O). Both the equation (via coefficients) and model (via molecule counts) confirm the number of each atom is equal in reactants and products.

Answer:

Reactants: \( \text{CH}_4 \) (methane) and \( \text{O}_2 \) (oxygen, 2 molecules).
Products: \( \text{CO}_2 \) (carbon dioxide) and \( \text{H}_2\text{O} \) (water, 2 molecules).

Question 7