Question

According to Arrhenius theory, acids and bases release H+ ions and OH- ions respectively in aqueous solution. However, their relative strengths are expressed in terms of pH value which is mathematically negative logarithm of H+ ion concentration. Infact, there is a scale known as pH scale which ranges from zero to 14. Solution with pH equal to 7 is regarded as neutral solution. Solution with pH less than 7 is acidic while the one with pH more than 7 is regarded as basic. It may be noted that more acidic is a solution, lesser will be its pH . The more alkaline is a solution, higher will be its pH value. Name an antacid that can neutralize the effect of acidity in the stomach?

Answer 1

1. Acidity happens when the gastric glands in the stomach release hydrochloric acid $\left(\mathrm{HCl}\right)$ more than required for the process of digestion.
2. The antacid is simply a salt or salt-like compound which neutralizes the acid produced in the stomach.
3. Usually, antacid helps in the prevention of acidity in the stomach.
4. Milk of magnesia $\left(\mathrm{Mg}{\left(\mathrm{OH}\right)}_2\right)$ is an antacid that reduces the acidity produced in the stomach.

Reaction involves:

$\mathrm{Mg}{\left(\mathrm{OH}\right)}_2\left(\mathrm{s}\right)+2\mathrm{HCl}\left(\mathrm{aq}\right)\underset{}{\to }2{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)+{\mathrm{MgCl}}_2\left(\mathrm{aq}\right)$

Thus, the Milk of magnesia is an antacid that helps in neutralizing the effect of acidity in the stomach.