Gastric juice contains 3g `HCl` per liter. If a person produces 2.5 L of gastric juice per day, how many antacid tables each containing 400 mg of `Al(OH)_(3)` are needed to neutralize all the `HCl` produced in one day ?

Explanation

HCl is neutralized by `Al(OH)_(3)` according to the equation,
`underset(27+3xx17=78g)(Al(OH)_(3))+underset(3xx36.5=109.5g)(3HCl)rarrAlCl_(3)+3H_(2)O`
HCl produced from 2.5 litre of gastric juice `=3.0xx2.5=7.5g`
109.5 g HCl is neutralized by `Al(OH)_(3)=78g`
`therefore" 7.5 g HCl will be neutralized by "Al(OH)_(3)=(78)/(109.5)xx7.5g=5.342g=5342mg`
`therefore" Number of tablets required "=(5342)/(400)=13.35, " i.e., 14 tablets."`