Question

The composition of Black damp is

• A. CO\(_2\) + N\(_2\)
• B. CO\(_2\) + H\(_2\)
• C. CO\(_2\) + CO
• D. CO\(_2\) + CH\(_4\)

Hint:

Remember the common mine "damps":
- Firedamp = Methane (CH\(_4\)), because it's flammable.
- Whitedamp = Carbon Monoxide (CO), a toxic gas.
- Blackdamp = CO\(_2\) + N\(_2\) (and low O\(_2\)), because it extinguishes flames.
- Stinkdamp = Hydrogen Sulphide (H\(_2\)S), because of its rotten egg smell.

Answer 1

The Correct Option is A

Step 1: Understanding the Question:
We need to identify the main components of the mine gas mixture known as "black damp".

Step 2: Detailed Explanation:
"Damp" is an old mining term for gas.

Black damp is not a single gas but an atmosphere that is deficient in oxygen.
It is formed when oxygen is removed from the air by processes like the slow oxidation of coal, decay of timber, or respiration.
As oxygen (O\(_2\)) is consumed, the remaining components of air, primarily Nitrogen (N\(_2\)), become more concentrated.
The oxidation process also produces Carbon Dioxide (CO\(_2\)).
Therefore, black damp is essentially an atmosphere consisting of an excess of

Nitrogen and

Carbon Dioxide, with a corresponding deficiency of Oxygen.
It is called "black" damp because it extinguishes the flame of a safety lamp, plunging a miner into darkness.

Step 3: Final Answer:
The primary components of black damp are carbon dioxide (CO\(_2\)) and nitrogen (N\(_2\)).
This corresponds to option (A).