Question

hydrogen peroxide can be used to disinfect and clean surfaces around the home. it breaks down over time into oxygen gas and water. consider the following reaction: some amount of hydrogen peroxide (h₂o₂) breaks down to produce 2 molecules of oxygen (o₂) and 4 molecules of water (h₂o). complete the table below. during this reaction, how many molecules of hydrogen peroxide (h₂o₂) react?

Explanation:

Step1: Calculate the number of H atoms

Each water (\(H_2O\)) molecule has \(2\) H atoms. There are \(4\) water molecules. So the number of H atoms from water is \(2\times4 = 8\). Since hydrogen peroxide (\(H_2O_2\)) is the only reactant with H atoms (and all H atoms in products come from \(H_2O_2\)), the number of H atoms in the reaction is \(8\).

Step2: Calculate the number of O atoms

Each oxygen (\(O_2\)) molecule has \(2\) O atoms (so \(2\) molecules of \(O_2\) have \(2\times2=4\) O atoms) and each water (\(H_2O\)) molecule has \(1\) O atom (so \(4\) molecules of \(H_2O\) have \(4\times1 = 4\) O atoms). The total number of O atoms in products is \(4 + 4=8\). Since all O atoms in products come from \(H_2O_2\), the number of O atoms in the reaction is \(8\).

Step3: Calculate the number of \(H_2O_2\) molecules

Each \(H_2O_2\) molecule has \(2\) H atoms. We know there are \(8\) H atoms in total (from Step1). So the number of \(H_2O_2\) molecules \(n=\frac{8}{2}=4\) (because each \(H_2O_2\) donates \(2\) H atoms to form water). Also, checking O atoms: each \(H_2O_2\) has \(2\) O atoms. With \(4\) \(H_2O_2\) molecules, there are \(4\times2 = 8\) O atoms (matches Step2 result).

Answer:

• For the number of H atoms: \(8\)
• For the number of O atoms: \(8\)
• For the number of \(H_2O_2\) molecules: \(4\)