Question

Gastric juice contains about 3.0 g of HCl per liter. If a person produces about 2.5 liter 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? Atomic mass of Cl = 35.5 ; Al = 27; O =16; H =1.

Answer 1

From the given,

Molar mass of HCl = 36.5 g/mol

${ N }_{ HCl }\quad in\quad gastric\quad juice\quad =\quad \frac { 3 }{ 36.5 }$

$Equivalent\quad weight\quad of\quad HCl\quad =\frac { 3 }{ 36.5 } \times 2500$

$=\quad 205.48\\ \frac { w }{ 78/3 } \quad \times \quad 1000\quad =\quad 205.48\\ { W }_{ Al(OH{ ) }_{ 3 } }\quad =\quad 5.342g\quad =\quad 5342\quad mg\\ Number\quad of\quad tablets\quad =\quad Al(OH{ ) }_{ 3 }\quad =\quad \frac { 5342 }{ 400 } \quad =\quad 13.34\quad \approx \quad 14\quad tablets$

Therefore, 14 antacid tablets each containing 400 mg of $Al(OH{ ) }_{ 3 }$ are needed to neutralized all the HCl produced in one day.