The decomposition of hydrogen peroxide, H2O2, produces water and oxygen gas. write a balanced equation for this decomposition reaction
The correct answer and explanation is:
Balanced Equation: 2H2O2→2H2O+O22H_2O_2 \rightarrow 2H_2O + O_2
Explanation (300 words):
Hydrogen peroxide (H₂O₂) is a pale blue liquid often used as a disinfectant or bleaching agent. One of its important chemical properties is its ability to decompose into water (H₂O) and oxygen gas (O₂). This reaction can occur slowly at room temperature, but it is often accelerated by light, heat, or the presence of catalysts such as manganese dioxide (MnO₂) or catalase (an enzyme found in living tissues).
To understand the reaction, let’s examine the chemical components:
- Reactant: Hydrogen peroxide, H₂O₂
- Products: Water, H₂O, and oxygen gas, O₂
First, we write the unbalanced chemical equation: H2O2→H2O+O2H_2O_2 \rightarrow H_2O + O_2
Next, we balance the equation. Begin by counting atoms:
- Hydrogen: On the left, H₂O₂ has 2 hydrogen atoms. On the right, each H₂O has 2 hydrogen atoms.
- Oxygen: On the left, H₂O₂ has 2 oxygen atoms. On the right, H₂O has 1 oxygen atom, and O₂ has 2 oxygen atoms (but it’s a diatomic molecule, so it’s trickier to balance).
To balance the atoms:
- Place a coefficient of 2 in front of H₂O₂ to have 4 oxygen atoms and 4 hydrogen atoms. 2H2O2→H2O+O22H_2O_2 \rightarrow H_2O + O_2
- Now add a 2 in front of H₂O to get 4 hydrogen atoms and 2 oxygen atoms. 2H2O2→2H2O+O22H_2O_2 \rightarrow 2H_2O + O_2
Now the equation is balanced:
- Hydrogen: 4 atoms on both sides
- Oxygen: 4 atoms on both sides (2 from 2H₂O and 2 from O₂)
This decomposition is an example of a redox reaction, where oxygen is both oxidized and reduced. It’s an important process in biological systems and industrial chemistry.