Question

consider the following reaction:
some amount of hydrogen peroxide (h₂o₂) breaks down to produce 5 molecules of oxygen (o₂) and 10 molecules of water (h₂o).
complete the table below.

chemical element	number of atoms in the reaction
o	blank

during this reaction, how many molecules of hydrogen peroxide (h₂o₂) react?
blank

Explanation:

Part 1: Number of H atoms

Step1: Calculate H from H₂O

Each H₂O has 2 H atoms, 10 H₂O: \(10 \times 2 = 20\)

Step2: H from H₂O₂ (conserved)

H atoms in reaction = H from H₂O (since H₂O₂ is reactant, H only in H₂O product here) → 20

Part 2: Number of O atoms

Step1: O from O₂

5 O₂ molecules: \(5 \times 2 = 10\)

Step2: O from H₂O

10 H₂O: \(10 \times 1 = 10\)

Step3: Total O

Sum: \(10 + 10 = 20\)

Part 3: Molecules of H₂O₂

Step1: Use O conservation

Each H₂O₂ has 2 O atoms. Total O in products: 20. So H₂O₂ molecules: \(\frac{20}{2} = 10\) (or use H: 20 H atoms, each H₂O₂ has 2 H → \(\frac{20}{2} = 10\))

Answer:

s:

• H atoms: 20
• O atoms: 20
• H₂O₂ molecules: 10