Which of the following is a solution used in extinguishing systems?

Potassium carbonate is a solution used in extinguishing systems, particularly in fire suppression applications. It acts as an effective agent for combating fires involving flammable liquids and grease, primarily in cooking environments. When it is applied, potassium carbonate can break the chain reaction of combustion, forming a barrier that prevents oxygen from reaching the fuel and subsequently suffocating the fire.

This substance has specific advantages in fire suppression. It can absorb heat and produce a non-flammable foam when mixed with water, thereby enhancing its effectiveness in extinguishing fires. Furthermore, potassium carbonate is considered safe for use in various environments despite its strong fire-suppressing properties.

In contrast, other substances listed, while potentially useful in different contexts, do not specifically serve as effective fire suppression solutions in extinguishing systems. Sodium chloride is often used in other applications but is less effective in fire extinguishing scenarios. Calcium carbonate, typically used for its buffering properties, does not offer the same comprehensive fire suppression capability. Ammonium sulfate, although useful in certain chemical processes, is not commonly applied as a fire suppression agent.