Question

Gastric juice contains $0.03$ moles $HCl$ of per liter. If a person produces $2.5$L of gastric juice per day. How many antacid tablets each containing $400$mg of $Al(OH{)}_3$ are needed to neutralize all the $HCl$ produced in one day?

Answer 1

For neutralizing,

No. of $H^{+}=$ No. of $O{H}^{-}$

Total no. of moles of $HCl=MW$ of $Al(OH{)}_3$ total moles of $Al(OH{)}_3\times$ In each mole of $Al(OH{)}_3,3O{H}^{-}$ are present $\times$ No. of tablets

$0.03\times 2.5=\left(\frac{400\times {10}^{-3}}{78}\right)\times 3\times n$

$⟹n=\frac{78\times 0.03\times 2.5}{400\times {10}^{-3}\times 3}$

$⟹n=4.875$

So you need $5$ antacid tablets to neutralized.