Question

Which of the following substances is an antacid?
(a) $NaCl$
(b) $Mg{{(OH)}_{2}}$
(c) $HCl$
(d) ${{H}_{2}}S{{O}_{4}}$

Answer 1

Hint: Antacids are used to remove acidity from the stomach and the mostly commonly and widely used antacids are bases i.e. baking soda, alkali and alkaline-earth metals carbonates and hydroxides. Now you can easily get to know about its answer.

Complete answer:
First of let’s discuss what are antacids. By the antacids, we mean those chemical substances which neutralize excess acid in the gastric juices and give relief from acid indigestion, acidity, heart burns and gastric ulcers. Acidic stomach is good for good health, but excessive acidity in the stomach causes discomfort and thus, antacids remove the excess acid and raise the pH to an appropriate level in the stomach. The most commonly used antacid are weak bases and is baking soda in water and the others bases most widely used are aluminum hydroxide, magnesium trisilicate, sodium bicarbonate, potassium bicarbonates. The antacids are available in the form of liquids, gels or tablets. Generally, liquid antacids are more effective than tablets because they have great surface area available for interaction and neutralization of acid. In the given statement, all are acids except the magnesium hydroxide, $Mg{{(OH)}_{2}}$ which is a base and is , thus, an antacid.

Hence, from the above it is clear that option (b) is correct.

Note: The treatment of acidity with the antacids can control only the symptoms and not the cause. Therefore, with these metal salts, the patients cannot be treated easily and in the advanced stages, ulcers become life threatening and it's only treatment is removal of the affected part of the stomach.