Question

Which of the following is used in the preparation of ammonal? (a) \(\mathrm{NaOH}+\mathrm{CaO}\) (b) Al powder (c) \(\mathrm{Fe}_{2} \mathrm{O}_{3}\) (d) \(\mathrm{CaCN}_{2}+\mathrm{C}\) (graphite)

Short answer

The answer is (b) Al powder.

Step-by-step solution

Understand the Components of Ammonal

Ammonal is a mixture primarily used in explosives. It typically contains ammonium nitrate as the oxidizing agent, aluminum powder as the fuel, and an additional ingredient like charcoal or TNT.

Identify the Fuel Component in Options

In the options given, we are looking for a fuel component commonly used in explosive mixtures. Aluminum powder (Option B) is recognized for its high energy content and is often added to explosives to increase blast effects.

Match the Component to Ammonal Composition

Ammonal specifically requires aluminum powder as one of its key components to act as a fuel and enhance the explosive characteristics of the mixture.

Key concepts

Explosive Mixtures

Explosive mixtures are chemical combinations that react to produce a large amount of energy very quickly. This energy release comes in the form of an explosion, characterized by a rapid expansion of gases and a shock wave. These mixtures typically consist of a fuel and an oxidizer.

The fuel component is what burns, and the oxidizer helps that fuel ignite more vigorously than it would using just air. When mixed properly, the combination creates a highly reactive mixture that, once ignited, results in a powerful explosion. Some modern explosives, like ammonal, include specific components to tailor their explosive properties for certain uses.

Components of explosive mixtures can be tailored to enhance certain facets, such as the force of the explosion or its duration. In the case of ammonal, it includes ammonium nitrate (an oxidizer) and aluminum powder (a fuel), allowing it to produce a very powerful explosive force mainly used in blasting operations.

Aluminum Powder

Aluminum powder is a critical component in many explosive mixtures, serving as an efficient and powerful fuel. It oxidizes rapidly, releasing a large amount of energy and heat, which contributes to the explosive power of mixtures like ammonal. The metal is ground into a fine powder to increase its reactive surface area with oxidizers, further enhancing the mixture's combustive capabilities.

Some of the main reasons aluminum powder is favored in explosives include:

• High energy content: Its combustible capacity results in a more powerful blast.
• Reactivity: Fine aluminum particles oxidize rapidly, releasing a sudden burst of energy.
• Availability and affordability: Aluminum is relatively inexpensive and easy to obtain compared to other high-energy metals.

These properties make aluminum powder an indispensable choice in explosive mixtures, improving both efficiency and efficacy.

Oxidizing Agents

Oxidizing agents are substances that can accept electrons in chemical reactions, prompting other materials to oxidize, or "burn," more intensely. In the context of explosive mixtures, oxidizers play a crucial role by providing the extra oxygen needed to ignite the fuel component rapidly.

One major oxidizing agent used in the preparation of explosive materials like ammonal is ammonium nitrate. This compound provides a reliable source of oxygen to react with aluminum powder efficiently. The presence of an oxidizer enables the mixture to produce a robust explosive reaction with minimal delay from ignition to detonation.

Characteristics that define an effective oxidizing agent in explosives include:

• High oxygen content: To maximize the reaction with the fuel.
• Stability: Should be stable under normal conditions, reducing accidental risk.
• Ease of mixing: To blend evenly with fuel for consistent explosive behavior.

These agents are essential in achieving controlled reactions, making them integral in safe and efficient explosive applications.