alleryStart learning →Which side effect is linked to a magnesium hydroxide antacid rather than an aluminium hydroxide one?
AIt tends to cause constipation instead
BIt can act as a laxative on the user
CIt releases carbon dioxide as it works
DIt leaves a strongly basic stomach behind
Answer & Solution
Correct answer: B. It can act as a laxative on the user
1. Magnesium hydroxide is a sparingly soluble base that supplies hydroxide ions.
2. Those ions react with stomach hydronium ions to form water, so no gas is released.
3. Antacids containing magnesium can have a laxative effect on the user.
4. Aluminium hydroxide has the opposite tendency and can cause constipation.
5. Some products combine the two so that the side effects offset one another.
6. Carbon dioxide comes from carbonate antacids such as calcium carbonate instead.
_Source: OpenStax Chemistry (CC BY 4.0), Ch 14 "Acid-Base Equilibria", section 14.4 Hydrolysis of Salt Solutions_
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