To determine which compound is used as a chemical in certain types of fire extinguishers, we need to understand the role of each compound listed in the options:
Baking soda (Sodium bicarbonate): When baking soda is heated, it decomposes to release carbon dioxide gas, which does not support combustion. This property makes baking soda effective in putting out fires by suffocating them, especially in small-scale fires. It is commonly used in portable fire extinguishers.
Soda ash (Sodium carbonate): This is used primarily in glass manufacturing and water softening. It does not have the property of releasing carbon dioxide gas like baking soda, so it is not typically used in fire extinguishers.
Washing soda (Sodium carbonate decahydrate): Similar to soda ash but with water of crystallization, washing soda is used mainly for cleaning and has no significant role in fire suppression.
Caustic Soda (Sodium hydroxide): This is a strong base commonly used as a chemical reagent and in cleaning but is highly corrosive and not suitable for use in fire extinguishers.
Conclusion: The correct answer is Baking soda, as it releases carbon dioxide on decomposition, which helps in extinguishing fires.
