Question

# Which gas evolves from fire extinguishers?A.${\text{C}}{{\text{O}}_{\text{2}}}$B.${\text{CO}}$C.${\text{C}}{{\text{O}}_{\text{3}}}$D.${{\text{H}}_{\text{2}}}$

The most common types of fire extinguishers contain either nitrogen or carbon dioxide gas under pressurized conditions to propel a stream of the fire-quenching agent to the fire. The active material maybe potassium bicarbonate ${\text{KHC}}{{\text{O}}_{\text{3}}}$, liquid water, or evaporating fluorocarbon or the propelling agent itself which is either carbon dioxide gas or the nitrogen gas. The reason for using carbon dioxide in fire extinguishers is that, when the gas is released from the extinguishers, it looks like dry ice. The cloud of carbon dioxide reduces the oxygen in the air around the fire thereby not allowing the fire to spread. However, this type of extinguishers do not work well outside due to the drift by the wind.