Question

Which of the following bases is used as an antacid to neutralize stomach acidity?
A.) $Mg{{\left( OH \right)}_{2}}$
B.) $KOH$
C.) $Ca{{\left( OH \right)}_{2}}$
D.) $NaOH$

Answer 1

Hint: Antacids are a class of medicines that neutralize acid in the stomach. They contain ingredients such as aluminium, calcium, magnesium, or sodium bicarbonate which act as bases (alkalis) to counteract stomach acid.
- Strong bases are not used as antacids as they can disturb the pH of the vital organs and stomach in the body and may damage the organs.
 - $KOH$, $Ca{{\left( OH \right)}_{2}}$ and $NaOH$ are all strong bases which completely ionize in water.

Complete Solution :
- An Antacid reacts with the excess acid developed in the body and neutralizes it and gives relief to the person. Antacids are available as liquids or tablets. Some products combine several antacid ingredients together or include alginates.
- Among the substances given in the question, strong bases $KOH$, $Ca{{\left( OH \right)}_{2}}$ and $NaOH$ are not used as an antacid because they have pH $13-14$ which can certainly damage the internal organs and disturb the pH of the body .
- Whereas weak bases like $Mg{{\left( OH \right)}_{2}}$ also known as milk of magnesia is commonly used as an antacid to give relief from acidity. It is also less soluble in water, it does not disturb the pH of the body like other strong bases.
So, the correct answer is “Option A”.

Note: There are other antacids too which are widely used like aluminium hydroxide, Aluminium hydroxide and magnesium carbonate.
- There are some disadvantages of taking antacids like some antacids contain sodium bicarbonate which can affect blood pressure and circulation, particularly those with pre-existing problems. High intakes of sodium are also not recommended for people with liver or kidney disease.