Which of the following is a correct use of baking soda (sodium hydrogen carbonate) in daily life?

Correct option is C

The correct answer is (C) It is used in fire extinguishers to produce foam

Explanation:
• Baking soda (sodium hydrogen carbonate, NaHCO3) is a mild, non-corrosive basic salt.
• A major application of baking soda is in soda-acid fire extinguishers. In these devices, baking soda is kept in a separate container alongside a strong acid (like sulfuric acid).
• When the extinguisher is triggered, the acid reacts vigorously with the baking soda to liberate massive amounts of carbon dioxide (CO2) gas.
• The CO2 gas, which does not support combustion and is heavier than air, forcefully exits the nozzle (often creating foam if surfactants are added) and blankets the fire, cutting off its oxygen supply.

Information Booster:
• Culinary Use: Baking soda is used in baking cakes and bread. When heated, it decomposes to produce CO2 bubbles, making the dough rise and become soft and spongy.
• Antacid: Being mildly basic, it is an active ingredient in antacids to neutralize excess hydrochloric acid in the human stomach, relieving indigestion.

Additional Knowledge:
• Option A: Common edible salt (NaCl) is harvested from seawater or rock salt, not "prepared" using baking soda.
• Option B: Soaps are made by saponification using strong alkalis like Sodium Hydroxide (NaOH) or Potassium Hydroxide (KOH), not baking soda.
• Option D: While it can neutralize acids in emergency spills, it is not an internal component used to "neutralize strong acids in lead-acid batteries" as part of the battery's function.