Problem 91 - A Complete Resource Book in Chemistry for JEE Main

Question

A certain metal \(\mathrm{M}\) is used to prepare an antacid, which is used as a medicine for acidity. This metal accidently catches fire, which can not be extinguished by using \(\mathrm{CO}_{2}\) based extinguishers. The metal \(\mathrm{M}\) is (a) \(\mathrm{Mg}\) (b) \(\mathrm{Ba}\) (c) \(\mathrm{Be}\) (d) \(\mathrm{C}\)

Step-by-Step Solution

Answer

The metal M is Magnesium (Mg).

Step 1: Identify the Properties of Metal M

We need to identify a metal used in antacids and understand its unique properties. Antacid metals typically react with acid to neutralize them, so metals like Magnesium (Mg) are common in these medicines.

Step 2: Fire Extinguisher Incompatibility

The problem states that the metal catches fire and can't be extinguished using a CO2-based extinguisher. Magnesium is known for burning with a bright flame and cannot be put out with CO2 doses, as it can react with CO2.

Step 3: Eliminate Other Options

Evaluate the other options: Barium (Ba) and Beryllium (Be) are not common in antacids, and neither reacts with CO2 in the same way. Carbon (C), in the form of graphite, can catch fire, but it's not a metal typically associated with antacids.

Step 4: Conclude the Choice

Given the properties and uses, Magnesium (Mg) is a metal used in antacids and is known to catch fire—a property making it unextinguishable with CO2-based methods.

Key Concepts

Magnesium properties

Magnesium is a fascinating element that finds its place in many applications, including medicine and industry. This lightweight, silvery-white metal is renowned for its distinct properties.
Magnesium is the ninth most abundant element in the earth's crust, making it widely available for various uses. One of the hallmark qualities of magnesium is its high reactivity, particularly with oxygen. It burns with an intense white flame, which is why it's often used in fireworks and flares. This same property also makes magnesium difficult to extinguish with standard methods when it catches fire.

• Lightweight and strong, making it useful in the aviation industry as well.
• Highly reactive, especially when powdered or in the form of thin ribbons.
• Essential for various biological processes in human beings.

Magnesium's unique properties make it both a critical industrial material and a crucial element in biological systems.

Fire safety of metals

Understanding the fire safety of metals, particularly reactive ones like magnesium, is essential for safe handling and application. Magnesium fires pose unique challenges due to the metal's ability to burn at high temperatures and react with traditional firefighting chemicals.
When magnesium ignites, it produces a very bright light and high heat. Attempting to extinguish a magnesium fire with water or carbon dioxide is ineffective and can even be dangerous, as magnesium can react with CO2 and water, exacerbating the fire.

• Special dry powder extinguishers are commonly used for metallic fires.
• Metals like magnesium should be stored carefully to prevent accidental ignition.
• It's important to train personnel in proper fire safety protocols when working with reactive metals.

Preventive measures and understanding the appropriate extinguishing techniques are critical in managing the risks associated with metal fires.

Antacid chemistry

Antacids are medications designed to alleviate symptoms caused by stomach acid, such as heartburn and indigestion. They typically work by neutralizing excess stomach acid, providing quick relief.
The chemistry behind antacids involves basic compounds that react with hydrochloric acid in the stomach. Magnesium hydroxide (Mg(OH)2) is a common active ingredient as it effectively reduces acidity and is fast-acting.

• Antacids are often formulated with a balance of different compounds to optimize effectiveness and minimize side effects.
• Magnesium-based antacids tend to work quickly and are known for having a laxative effect, unlike aluminum-based alternatives.
• Proper dosages are crucial to prevent imbalances and ensure the relief of symptoms without adverse effects.

In understanding the role of metals like magnesium in antacids, it's apparent how the element's properties are harnessed for therapeutic purposes.