Question

\(\mathrm{HCl}\) is added to the following oxides, which of them will give \(\mathrm{H}_{2} \mathrm{O}_{2} ?\) (1) \(\mathrm{Na}_{2} \mathrm{O}_{2}\) (2) \(\mathrm{BaO}\) (3) \(\mathrm{BaO}_{2}\) (4) \(\mathrm{MnO}_{2}\) (a) 1,2 (b) 1,3 (c) \(1,2,3\) (d) I only

Short answer

Option (b) 1,3: \( \mathrm{Na}_2\mathrm{O}_2 \) and \( \mathrm{BaO}_2 \) will produce \( \mathrm{H}_2\mathrm{O}_2 \).

Step-by-step solution

Analyze the Question

The question asks which of the given oxides will produce hydrogen peroxide (\( \mathrm{H}_2\mathrm{O}_2 \)) when reacted with hydrochloric acid (\( \mathrm{HCl} \)). Hydrogen peroxide is commonly formed from metal peroxides when they react with acids.

Identify Possible Peroxides

Determine which of the options may contain a peroxide. Option (1), \( \mathrm{Na}_2\mathrm{O}_2 \), is sodium peroxide, and option (3), \( \mathrm{BaO}_2 \), is barium peroxide, both of which are known peroxides.

Reactions with Hydrochloric Acid

Consider the reaction of each identified peroxide with \( \mathrm{HCl} \):- \( \mathrm{Na}_2\mathrm{O}_2 + 2 \mathrm{HCl} \rightarrow 2 \mathrm{NaCl} + \mathrm{H}_2\mathrm{O}_2 \)- \( \mathrm{BaO}_2 + 2 \mathrm{HCl} \rightarrow \mathrm{BaCl}_2 + \mathrm{H}_2\mathrm{O}_2 \)Both reactions produce hydrogen peroxide.

Eliminate Non-Peroxides

Options (2) \( \mathrm{BaO} \) and (4) \( \mathrm{MnO}_2 \) are not peroxides. They do not produce \( \mathrm{H}_2\mathrm{O}_2 \) when reacted with \( \mathrm{HCl} \).

Key concepts

Peroxides

Peroxides are distinct chemical compounds featuring an otable peroxide ion, \ ext{O}_2^{2-}\, paired with a metal. They are classified as a specific type of oxide with an oxygen-oxygen single bond. This is unique and gives peroxides their reactive character.

Metal peroxides, like sodium peroxide \( ext{Na}_2 ext{O}_2\) and barium peroxide \( ext{BaO}_2\), react readily with water or acids to form hydrogen peroxide \( ext{H}_2 ext{O}_2\). The presence of the peroxide ion makes them suitable for specific reactions where oxygen release is desired.

When choosing a chemical capable of producing hydrogen peroxide upon reaction, look for peroxides within the list of compounds. This is due to their decomposition properties under acidic conditions.

Chemical Reactions

Chemical reactions involving peroxides demonstrate unique behavior due to the special structure of the peroxide ion. These reactions typically form products that are different from those of normal oxides.

One hallmark chemical reaction to note is the reaction of peroxides with hydrochloric acid \( ext{HCl}\), resulting in the formation of hydrogen peroxide \( ext{H}_2 ext{O}_2\) along with salt by-products, such as sodium chloride in the case of sodium peroxide.

• For sodium peroxide, the reaction goes: \\( ext{Na}_2 ext{O}_2 + 2 ext{HCl} \rightarrow 2 ext{NaCl} + ext{H}_2 ext{O}_2 \)
• For barium peroxide, the reaction is: \\( ext{BaO}_2 + 2 ext{HCl} \rightarrow ext{BaCl}_2 + ext{H}_2 ext{O}_2 \)

Such reactions underscore the reactivity of peroxides and their significance in synthesizing hydrogen peroxide from available compounds.

Oxides and Acids

Oxides are compounds formed by the reaction of oxygen with elements, most often metals. They can come in various forms, such as basic oxides, peroxides, or dioxides.

When oxides react with acids, they usually form salts and water, but certain oxides like peroxides yield hydrogen peroxide \( ext{H}_2 ext{O}_2\). These interactions are vital in many chemical processes and applications.

• Basic oxides, such as magnesium oxide \( ext{MgO}\), generally produce salts and water when reacting with acids.
• Peroxides, as explained in previous sections, produce an additional useful product – hydrogen peroxide \( ext{H}_2 ext{O}_2\).

Understanding the distinct reactions between different oxides and acids enables the synthesis of various products and is crucial for mastering inorganic chemistry.