Question

Which of the following statements are correct about Hydrogen peroxide

1. i) Colourless gas at room temperature.
2. ii) Powerful oxidising and weak reducing agent.
3. iii) Its stability is increased by making it slightly acid and addition of small quantities of preservatives.

1. i) Colourless gas at room temperature.
2. ii) Powerful oxidising and weak reducing agent.
3. iii) Its stability is increased by making it slightly acid and addition of small quantities of preservatives.

• A. 2, 3
• B. 1, 2
• C. All
• D. 2 only

Answer 1

Answer:

A. 2, 3

• Statement i is false: At room temperature, hydrogen peroxide ($\text{H}_2\text{O}_2$) is actually a clear, colorless liquid (slightly more viscous than water), not a gas.

• Statement ii is true: $\text{H}_2\text{O}_2$ is a highly powerful oxidizing agent. While it can act as a reducing agent in the presence of even stronger oxidizers, its reducing capability is relatively weak compared to its oxidizing strength.

• Statement iii is true: Pure hydrogen peroxide is chemically unstable and tends to decompose into water and oxygen gas ($\text{2H}_2\text{O}_2 \rightarrow \text{2H}_2\text{O} + \text{O}_2$). Making the solution slightly acidic and adding tiny amounts of stabilizers/preservatives (like acetanilide or sodium stannate) keeps it stable on the shelf.