Sometimes, indigestion is caused by the secretion of too much hydrochloric acid in the stomach. To ease the pain caused, a tablet can be taken that reacts to reduce the amount of acid present. Which one among the following would be inappropriate for a manufacturer to include as a major reactant in the tablet?

Indigestion caused by excess hydrochloric acid (HCl) is treated using antacids, which are mild bases that neutralize the acid [2]. Common active ingredients in antacid tablets include magnesium hydroxide [Mg(OH)2], calcium carbonate [CaCO3], and magnesium carbonate [MgCO3] [1]. These substances are chosen because they are relatively weak bases or insoluble salts that react safely within the stomach to form water, carbon dioxide, and neutral salts [3]. In contrast, sodium hydroxide (NaOH) is a strong, highly caustic base. Unlike mild antacids like Milk of Magnesia [1], NaOH can cause severe chemical burns to the esophagus and stomach lining upon ingestion. Therefore, while it would technically neutralize acid, its corrosive nature makes it entirely inappropriate and dangerous for use as a reactant in medicinal tablets intended for human consumption.

Sources

1. [1] Science , class X (NCERT 2025 ed.) > Chapter 2: Acids, Bases and Salts > pH in our digestive system > p. 27
2. [2] Science , class X (NCERT 2025 ed.) > Chapter 2: Acids, Bases and Salts > Uses of Baking soda > p. 31
3. [3] Science , class X (NCERT 2025 ed.) > Chapter 2: Acids, Bases and Salts > Activity 2.5 > p. 21