Question

Milk of magnesia neutralizes the effect of:
(A) acid
(B) base
(C) alkali
(D) salt

Answer 1

Milk of magnesia is the common name of the inorganic compound magnesium hydroxide. Its chemical formula is $Mg{(OH)_2}$ . It is a white solid that is very less soluble in water. It is a very common component of antacids and laxatives.

Complete answer
Milk of Magnesia is prepared by a combination of solutions of magnesium salts with alkaline water. The net chemical reaction results in the formation of solid milky precipitation of magnesia. The chemical reaction for this process is;
$2O{H^ - } + M{g^{2 + }} \to Mg{(OH)_2}\,(milk\,of\,magnesia)$
The commercial production of milk of magnesia is done with the help of calcium hydroxide which is also known as lime. The milk of magnesia precipitated from $CaOH$ is solid because it is more soluble in water as compared to the Magnesium Hydroxide.
Milk of magnesia is used for medicinal use in the form of chewable pills, capsules, powder, and liquid suspension. It is used to neutralize the acid produced in the stomach due to indigestion causing stomach disorder and acidity. To get relief from this acidity or indigestion, milk of magnesia is taken as an antacid. You can also use it as a laxative to get relief from constipation. Being alkaline in nature it reacts with the acid present in the stomach to alleviate indigestion and burning in the stomach.
Hence we can say that Milk of Magnesia neutralizes the effect of acid. Therefore, option (A) is acid.

Note
Milk of magnesia can also be used in the form of Epsom salts in the treatment of rashes. It is also used industrially in the neutralization of acidic wastewater. It is also used as a fire retardant. This compound is very essential in the oxidation process for the production of energy in the animal cell.