Which mineral salt is commonly used as an antacid and to buffer acid in emergencies?

• A. Magnesium sulfate
• B. Sodium bicarbonate
• C. Calcium chloride
• D. Hepatitis B vaccine

Answer: (B)

Sodium bicarbonate is used for both neutralizing acid directly and helping maintain pH in emergency situations. When it dissolves, it releases bicarbonate ions that react with hydrogen ions to form carbonic acid, which then breaks down into water and carbon dioxide. This reaction reduces acidity and raises the pH, so it acts as an effective antacid and as a buffering agent in acidosis or toxin-related acidemia encountered in emergencies. The other minerals listed don’t serve this buffering role: magnesium sulfate and calcium chloride have different primary uses as electrolytes and laxatives, while a vaccine isn’t related to acid buffering.