Question

Give an example of a substance which does not contain acid.

Answer 1

Hint: We know that Antacids are bases; they do not contain any acids. The substances which neutralize the acids of the stomach are called antacids. Acidity in the stomach causes the sensation of heartburn; antacids are taken to relieve this sensation.

Complete answer:
Now, first let us define antacids. These are used in the treatment of acidity caused in the stomach. If we say when the excess of acid is produced in the stomach mainly, there will be a feeling of irritation, and it will eventually cause pain in the stomach. They are taken orally to suppress the after effects of acidity. Antacids are actually alkaline ions that directly neutralize the gastric acids of the stomach.
Thus, we can say from the name too, antacids i.e. anti and acids, which means it shows the opposite effect to acids. Therefore, sometimes the acidity causes ulcers in the stomach. So, if we say antacids are opposite of acids, it means that antacids are the base in nature. Few examples of antacids are
-Calcium carbonate
-Aluminium hydroxide gel

Note:
Remember that there could be a confusion that if the sodium hydroxide is a base, then why it is not used as an antacid. So, when it was used as an antacid, then it was proved to be harmful for the digestive tract. Thus, it is not used as an antacid in the individual form.