Answer :
Final answer:
The correct classification of portable fire extinguisher for fires involving combustible metals and alloys is Class D. These extinguishers are specially formulated with agents such as sodium chloride granules to handle the high reactivity of burning metals, unlike other classes meant for different types of fires. Option (C) is correct.
Explanation:
The classification of portable fire extinguisher used for fires that involve combustible metals and alloys is Class D. These types of fires typically involve materials such as magnesium, titanium, sodium, and potassium. Class D extinguishers contain extinguishing agents specifically designed to deal with the high temperatures and reactivity of burning metals. Common agents include sodium chloride (salt) granules, copper-based powders, or other specialized dry powder extinguishing agents.
It is essential to use the correct extinguisher classification, as using water, a common extinguishing medium for other classes of fire (like Class A), could result in a violent reaction when applied to a metal fire. Additionally, other classes like Class A (for paper, wood, cloth), Class B (flammable liquids and gases), and Class K (cooking oils and fats) are not suitable for metal fires.
Within the topic of hydrides such as Metallic Hydrides, Saline Hydrides, and Covalent Hydrides, which are compounds that can contain combustible metals, awareness and preparedness for potential fires with appropriate extinguishing agents are imperative.
