Question

The gas which may cause explosion in coal mines is :

• A. Methane
• B. Ethane
• C. Nitrogen
• D. Oxygen

Hint:

The primary flammable gas responsible for explosions in coal mines is {Methane (\(\text{CH}_4\))}, also known as "firedamp." Oxygen is needed for the explosion (as an oxidizer), but it is not the fuel. Methane is the fuel. Coal dust explosions are another significant hazard.

Answer 1

The Correct Option is A

Concept: Coal mines can contain flammable gases trapped within the coal seams. When these gases mix with air in certain proportions, they can form explosive mixtures. Step 1: Gases found in Coal Mines Coal formation processes can trap various gases. The most significant flammable gas found in coal mines is Methane (\(\text{CH}_4\)). Methane is the main component of natural gas. In coal mines, methane is often referred to as "firedamp." Another major hazard is coal dust itself, which can also be explosive when suspended in air in sufficient concentrations. Step 2: Conditions for Explosion For a gas to cause an explosion, it must be: % Option (A) Flammable (able to burn). % Option (B) Mixed with an oxidizer (usually oxygen from the air) in proportions that fall within its explosive or flammability limits. % Option (C) Ignited by a source of ignition (like a spark, open flame, or hot surface). Step 3: Analyzing the options % Option (D) (1) Methane (\(\text{CH}_4\)): Methane is highly flammable and forms explosive mixtures with air. It is a well-known and primary cause of explosions in coal mines (firedamp explosions). % Option (E) (2) Ethane (\(\text{C}_2\text{H}_6\)): Ethane is also a flammable gas and can be present with methane, but methane is typically the predominant flammable gas associated with coal mine explosions. % Option (F) (3) Nitrogen (\(\text{N}_2\)): Nitrogen is an inert gas; it does not burn and is not explosive. It's the main component of air. % Option (G) (4) Oxygen (\(\text{O}_2\)): Oxygen is necessary for combustion (it's an oxidizer), but oxygen itself is not flammable or explosive. It supports the combustion of flammable substances. The image indicates this option was circled, which is incorrect as oxygen supports combustion but isn't the fuel itself for an explosion in this context. Step 4: Identifying the primary cause of explosions Methane (\(\text{CH}_4\)) is the gas most notorious for causing explosions in coal mines. When mixed with air (which contains oxygen) in concentrations roughly between 5% and 15% methane, it can be ignited and explode violently.