Among statements (A) - (D), the correct ones are
(A) decomposition of hydrogen peroxide gives dioxyg

Q: Why does hydrogen peroxide decompose so easily?

The O-O peroxide bond is relatively weak and unstable. When exposed to light or heat, it readily undergoes disproportionation to form more stable molecules: water and oxygen gas.

Q: Do all nitrates give oxygen on heating?

Most nitrates decompose on heating to give oxygen, but the other products vary. Alkali metal nitrates (like $NaNO_3$) give nitrites and oxygen, while heavy metal nitrates (like $Pb(NO_3)_2$) give metal oxides, nitrogen dioxide, and oxygen.

Q: What is the role of 2-ethylanthraquinone in the industrial process?

It acts as a cyclic intermediate. 2-ethylanthraquinone is first reduced to 2-ethylanthraquinol using hydrogen gas and a catalyst. Then, it is oxidized by air back to the quinone, releasing hydrogen peroxide in the process.

Q: Why is sodium perborate used in detergents?

Sodium perborate acts as a stable source of active oxygen. When dissolved in water, it releases hydrogen peroxide, which acts as a mild, color-safe bleach to remove stains.

Q: Is hydrogen peroxide an oxidizing or reducing agent?

It can act as both! Because the oxygen in $H_2O_2$ is in the -1 oxidation state, it can be reduced to -2 (in $H_2O$) acting as an oxidizing agent, or oxidized to 0 (in $O_2$) acting as a reducing agent.

Question

Among statements (A) - (D), the correct ones are
(A) decomposition of hydrogen peroxide gives dioxygen.
(B) like hydrogen peroxide, compounds, such as $	ext{KClO}_3$, $	ext{Pb}(	ext{NO}_3)_2$ and $	ext{NaNO}_3$ when heated liberate dioxygen.
(C) 2-ethylanthraquinone is useful for the industrial preparation of hydrogen peroxide.
(D) hydrogen peroxide is used for the manufacture of sodium perborate.

Options:

(A) (A), (B) and (C) only

(B) (A), (B), (C) and (D)

(C) (A), (C) and (D) only

(D) (A) and (C) only

Sigma Percentile · Accepted Answer

### The Chemistry of Hydrogen Peroxide

Hydrogen peroxide ($H_2O_2$) is one of the most versatile and fascinating compounds in inorganic chemistry. It acts as an oxidizing agent, a reducing agent, a bleaching agent, and even a mild antiseptic. In this problem, we are tasked with evaluating four distinct statements that cover its decomposition, its similarities with other oxygen-rich compounds, its industrial preparation, and its commercial applications.

Let's break down each statement to uncover the chemical truths behind them.

### Statement A: The Instability of $H_2O_2$

The first statement claims that the decomposition of hydrogen peroxide gives dioxygen.

Hydrogen peroxide is thermodynamically unstable. The peroxide bond ($-O-O-$) is relatively weak, making the molecule prone to disproportionation. When exposed to heat, light, or even certain metal catalysts, it readily breaks down into water and oxygen gas:

$$H_2O_2(l) \xrightarrow{\Delta} H_2O(l) + \frac{1}{2}O_2(g)$$

This is why hydrogen peroxide is always stored in dark, wax-lined bottles to prevent photolytic decomposition. Since it clearly produces dioxygen ($O_2$), **Statement (A) is absolutely correct.**

### Statement B: Thermal Decomposition of Oxygen-Rich Salts

The second statement compares hydrogen peroxide to compounds like potassium chlorate ($KClO_3$), lead nitrate ($Pb(NO_3)_2$), and sodium nitrate ($NaNO_3$), stating that they also liberate dioxygen upon heating.

Let's verify this by looking at their thermal decomposition reactions:

1. **Potassium Chlorate:** When heated, especially in the presence of a manganese dioxide ($MnO_2$) catalyst, it decomposes to yield potassium chloride and oxygen gas.
$$2KClO_3 \xrightarrow{\Delta} 2KCl + 3O_2$$

2. **Lead Nitrate:** Heating this heavy metal nitrate produces lead(II) oxide, brown fumes of nitrogen dioxide, and oxygen gas.
$$2Pb(NO_3)_2 \xrightarrow{\Delta} 2PbO + 4NO_2 + O_2$$

3. **Sodium Nitrate:** Alkali metal nitrates (except lithium) melt and decompose to form their corresponding nitrites and oxygen gas.
$$2NaNO_3 \xrightarrow{\Delta} 2NaNO_2 + O_2$$

Since all these compounds successfully liberate dioxygen upon heating, **Statement (B) is correct.**

### Statement C: The Industrial Masterpiece

Statement C brings us to the industrial preparation of hydrogen peroxide, claiming that 2-ethylanthraquinone is useful for this process.

This refers to the famous **auto-oxidation process**. In industry, hydrogen peroxide is not made by simple laboratory methods. Instead, a cyclic process is employed. First, 2-ethylanthraquinone is catalytically reduced using hydrogen gas to form 2-ethylanthraquinol.

Then, air (oxygen) is bubbled through the solution. The 2-ethylanthraquinol undergoes auto-oxidation, converting back into 2-ethylanthraquinone and simultaneously yielding hydrogen peroxide:

$$	ext{2-ethylanthraquinol} + O_2 ightarrow 	ext{2-ethylanthraquinone} + H_2O_2$$

The 2-ethylanthraquinone is then recycled back into the process. Because this is the primary industrial method, **Statement (C) is correct.**

### Statement D: Everyday Applications

The final statement asserts that hydrogen peroxide is used for the manufacture of sodium perborate.

Sodium perborate ($Na_2B_2O_4(OH)_4$) is a crucial ingredient in high-quality washing powders and detergents. It acts as a stable, solid source of active oxygen, providing excellent bleaching properties without damaging fabrics. It is manufactured by reacting sodium metaborate with hydrogen peroxide:

$$2NaBO_2 + 2H_2O_2 ightarrow Na_2B_2O_4(OH)_4$$

This confirms that hydrogen peroxide is indeed essential for its manufacture. Thus, **Statement (D) is correct.**

### The Final Verdict

After a thorough chemical analysis, we have found that all four statements—(A), (B), (C), and (D)—are completely accurate. They beautifully summarize the core properties, preparation, and uses of hydrogen peroxide. Therefore, the correct option is the one that includes all of them.

Select Answer:

Visualized Solution

\text{Analyzing Hydrogen Peroxide } (\text{H}_2\text{O}_2)

\text{Statement (A): Decomposition of } \text{H}_2\text{O}_2

\text{Statement (B): Thermal Decomposition of Salts}

\text{Statement (C): Industrial Preparation}

\text{Statement (D): Uses of } \text{H}_2\text{O}_2

\text{Final Conclusion}

The Sigma Insight: Hydrogen, Hydrides and Water

The Chemistry of Hydrogen Peroxide

Statement A

Statement B

Statement C

Statement D

The Final Verdict

Similar Questions

From the following statements regarding $H_{2} O_{2}$ , choose the incorrect statement.

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The chemical nature of hydrogen peroxide is

The correct statements about $H_{2} O_{2}$ are (A) used in the treatment of effluents. (B) used as both oxidising and reducing agents. (C) the two hydroxyl groups lie in the same plane. (D) miscible with water. Choose the correct answer from the options given below.

Hydrogen peroxide reacts with iodine in basic medium to give

(A) $HOCl + H_{2} O_{2} ⟶ H_{3} O^{+} + Cl^{-} + O_{2}$ (B) $I_{2} + H_{2} O_{2} + 2 OH^{-} ⟶ 2 I^{-} + 2 H_{2} O + O_{2}$ Choose the correct option.

The oxide that gives $H_{2} O_{2}$ most readily on treatment with $H_{2} O$ is

Hydrogen peroxide, in the pure state, is

The single largest industrial application of dihydrogen is